1559

1559 is a prime number. It is a Sophie Germain prime because 2 x 1559 + 1 = 3119 is also prime (A005384).

Reversing the digits of 1559 produces the prime 9551. 1559 is the smallest such prime that becomes a semiprime when any single digit is removed.

1559 is the smallest prime p with 16 consecutive quadratic residues mod p.

1559 is the number of different ways to divide an 11 x 11 square into sub-squares, considering only the list of parts (A034295).

1559 is 2010202 in base 3. It is 2122 in base 9.

Source: Prime Curios!

7296

7296 = 2 x 2 x 2 x 2 x 2 x 2 x 2 x 3 x 19.

7296 is a multiple of 24 whose digits also sum to 24 (A066270). The sum of the digits of 7296 equals the sum of the unique prime divisors of 7296 (A070275).

7296 is 5533 in base 11 and 2266 in base 15 (A033013).

7296 is the number of rooted polyhedral graphs with 15 edges (A000287).

7296 divides 65⁶ - 1.

Source: OEIS

4500

4500 = 2 x 2 x 3 x 3 x 5 x 5 x 5. It has exactly three distinct prime factors, none of which is greater than 5 (A143207).

4500 is the smallest base in which KJIHGFEDCBA987654321 is a prime. All shorter such strings achieve prime status in mch smaller bases (192 is the maximum required). Not until the string (110)(109)(108) . . . 321 is a higher base required.

4500 is the number of regions formed when all diagonals are drawn in a regular 20-gon (A007678).

4500 is a concentric icosagonal number (A195148).

4500 can be represented in bases 2, 3, 4, and 5 using only the digits 0, 1, and 2. It is 3421 in base 11.

4500 has two representations as a sum of two squares: 4500 = 12² + 66² = 30² + 60².

Source: Prime Curios!

3701

3701 is a prime number.

3701 is a prime that is the sum of seven consecutive primes (A082246).

3701 is the smallest prime with exactly 22 representations as a sum of three distinct positive squares (A242675).

3701 has a representation as a sum of two squares (A108655): 3701 = 26² + 55².

3701 is the hypotenuse of a primitive Pythagorean triple: 3701² = 2349² + 2860².

Source: OEIS

8111

8111 is a prime number. It is a Sophie Germain prime because 2 x 8111 = 16223 is also prime. Every digit of 8111 is a perfect cube (A061247 and A066592).

8111 is a prime that results from merging four successive digits in the decimal expansion of pi (A104824).

8111 is the concatenation of the first two digits and the last two digits of the 35th Mersenne prime (A138863).

8111 is 102010102 in base 3. It is 12112 in base 9 (A032930).

Source: OEIS

2004

2004 = 2 x 2 x 3 x 167.

2004 has a square with the last three digits the same as the three digits before them: 2004² = 4016016.

2²⁰⁰⁴ + 823 is a prime. It is the smallest prime of the form 2²⁰⁰⁴ + k. The reversal of 2²⁰⁰⁴ is a prime (A057708).

(2004 x 4002) - 1 is a prime.

2004 was a year in which there were five Sundays in the month of February (A119406).

Source: Prime Curios!

5325

5325 = 3 x 5 x 5 x 71.

5325 is a lucky number of only prime digits (A118718).

5325 and its reversal (5235) are both multiples of 15 (A062905).

The product of the digits of 5325 is 10 times the sum of the digits (A062043).

5325 is 21345 in base 7. It is 4001 in base 11.

5325 is the sum of the remainders when the 40th prime is divided by all preceding integers (A050482).

5325 divides 76⁵ - 1.

Source: OEIS

7289

7289 = 37 x 197.

7289 and each of its two divisors include the digit 7 (A062676).

7289 is 2929 in base 14.

7289 has two representations as a sum of two squares: 7289 = 8² + 85² = 20² + 83².

7289 is the hypotenuse of two primitive Pythagorean triples: 7289² = 1360² + 7161² = 3320² + 6489².

7289 divides 14¹² - 1.

Source: OEIS

7368

7368 = 2 x 2 x 2 x 3 x 307.

7368 is a multiple of 24 whose digits also sum to 24 (A066270).

7368 is 5599 in base 11.

7368 minus the sum of its unique prime factors is a square (A216894): 7368 - (2 + 3 + 307) = 7056 = 84².

7368 divides 17⁶ - 1.

7368 is the number of partitions of 52 such that the sum of the square of the parts is a square (A240127).

Source: OEIS

1847

1847 is a prime number.

1847 is the number of 2 x 2 x 2 Rubik's cube positions that require exactly four moves to solve.

1847 is 24342 (palindromic) in base 5. It is 737 in base 16 (A029732).

1847 is the sum of the first 50 nonprimes (A051349).

1847 is the lower prime of a difference of 14 between consecutive primes (A031932).

The first adhesive U.S. postage stamp went on sale in the year 1847. Thomas Edison was born in the year 1847 and died in the prime year 1931.

Source: Prime Curios!

2579

2579 is a prime number. It is a safe prime (A005385).

2579 is the smallest prime number that can be expressed as the sum of 13 consecutive Fibonacci numbers (the fourth to the sixteenth). It is also a prime that is the difference of two Fibonacci numbers (A113188).

2579 is the smallest prime that is equal to the sum of 35 consecutive primes (A070934).

2579 is 40304 in base 5 (A029973).

Source: Prime Curios!

7777

7777 = 7 x 11 x 101. It is a palindrome with exactly three distinct palindromic prime factors (A046409).

7777 has the representation 6⁵ + 1 (A062394). It is 100001 (palindromic) in base 6 (A029963 and A033043).

7777 divides 36⁵ - 1.

7777 is a number that is the sum of two positive fifth powers (A003347 and A004842).

7777 is a Kaprekar number (A006886).

Source: OEIS

1809

1809 = 3 x 3 x 3 x 67.

1809 is the sum of the first 26 palindromes (A046489).

1809 is the sum of the first 17 primes whose indices are primes (A083186).

1809 is a non-palindromic balanced number; the first and last half of its digits have the same sum (A145808).

1809 is a multiple of 9 that contains 9 in its decimal representation (A121029).

1809 is 3421 in base 8. It is 809 in base 15.

1809 divides 37³ - 1.

Source: OEIS

4391

4391 is a prime number. It is a Sophie Germain prime because 2 x 4391 + 1 = 8783 is also a prime.

4391 is the smaller of two consecutive Sophie Germain primes with the same digital sum (A118506).

4391 is the sum of the first 47 primes minus 47 (A101301).

4391 is a number that cannot be written as a sum of three squares.

4391 is 3332 in base 11 (A032811).

Source: OEIS

2504

2504 = 2 x 2 x 2 x 313.

2504 is 40004 in base 5 (A097251).

2504 is a Friedman number (A036057).

2504 is the number of forests of ordered trees on 9 total nodes (A052854).

2504 has a representation as a sum of two squares: 2504 = 2² + 50².

2504 divides 25⁴ - 1.

Source: What's Special About This Number?

1623

1623 = 3 x 541.

1623 is a number for which the sum of the reciprocals of its digits is an integer (A034708).

1623 is a number whose product of digits is three times the sum of its digits (A062035).

1623 is a semiprime that is the sum of three consecutive semiprimes (A131610).

1623 is a number that is not the sum of two triangular numbers and a fourth power (A115160).

1623 cannot be written as the sum of three squares.

1623 divides 52⁴ - 1.

Source: OEIS

9668

9668 = 2 x 2 x 2417.

9668 is the number of Sophie Germain primes among the first 10⁵ primes (A04940).

9668 is 112432 in base 6 and 14232 in base 9.

9668 has a representation as a sum of two squares: 9668 = 8² + 98².

9668 divides 67¹⁶ - 1.

Source: OEIS

8420

8420 = 2 x 2 x 5 x 421.

8420 is the number of symmetric ways to fold a strip of 20 stamps (A001010).

8420 = 20³ + 20² + 20 (A027444 and A063012).

8420 has two representations as a sum of two squares: 8420 = 26² + 88² = 32² + 86².

8420 divides 29⁴ - 1.

Source: What's Special About This Number?

3260

3260 = 2 x 2 x 5 x 163.

3260 is 23032 in base 6. It is 4422 in base 9 (A033007).

3260 is the number of inequivalent ways to cut an 11 x 11 square into squares with integer sides, such that the dissection has 90-degree rotational symmetry and no reflective symmetry (A240122).

3260 is a number that is not the sum of a triangular number, a cube, and a Fibonacci number (A115177).

3260 cannot be written as the sum of three squares.

3260 divides 59⁶ - 1.

Source: OEIS

1379

1379 = 7 x 197.

Dropping any digit of 1379 gives a prime number (A034895).

1379 is the maximum number of regions into which 52 lines divide the plane. It is a central polygonal numbers (A000124).

1379 is a heptadecagonal number (A051869).

1379 is the magic constant of a 24 x 24 normal magic square.

1379 is 4010 in base 7 and 1044 in base 11. It is 2543 in base 8 and 707 in base 14.

1379 divides 36⁷ - 1.

Source: What's Special About This Number?

4126

4126 = 2 x 2063.

4126 is 113001 in base 5 and 3111 in base 11 (A032918).

4126 is a number that contains the product of any two adjacent digits as a substring, and has at least one pair of adjacent digits (A203566).

4126 is the number of positions that are exactly 16 moves from the starting position in the "hockey puck" puzzle (A079735).

4126 is the number of primes between 34 and 34³ (A117491).

Source: OEIS

9703

9703 = 31 x 313.

9703 is 302303 in base 5. It is 40201 in base 7.

9703 is a number of the form n³ + n² + 1 for n = 21 (A098547).

9703 is a number that cannot be written as a sum of three squares.

9703 divides 98³ - 1.

Source: OEIS

5303

5303 is a prime number. It is a Sophie Germain prime because 2 x 5303 + 1 = 10607 is also a prime. The sum of the digits of 5303 (11) is also a Sophie Germain prime (A118504).

5303 is a balanced prime (the average of the previous prime and the following prime) (A006562). 5297, 5303, and 5309 are three consecutive primes (A053070).

5303 is a prime that is the sum of five consecutive composite numbers (A060330).

Source: OEIS

2017

2017 is a prime number.

2011 and 2017 are a sexy prime pair (differing by 6).

2017 is an odd central polygonal number (A193867).

2017 is the sum of four consecutive composite numbers (A060329).

2017 is a prime that remains a prime when a single "7" digit is inserted between any two adjacent digits (A217065).

2017 is a prime with digit sum 10 (A107579).

2017 has a representation as a sum of two squares: 2017 = 9² + 44².

2017 is the hypotenuse of a primitive Pythagorean triple: 2017² = 792² + 1855².

2017 divides 79⁷ - 1.

Source: OEIS

2003

2003 is a prime number. It is a Sophie Germain prime because 2 x 2003 + 1 = 4007 is also a prime.

2003 is formed from the first two primes (2 and 3) separated by two zeroes. Add 2³, then 2 x 3 to get the next two primes: 2011 and 2017.

The concatenation of numbers from 2000 to 2003 (2000200120022003) is a prime.

2003 is the only known prime of the form 2 x 10^p + p, where p and p + 4 are primes (with p = 3).

2003 is 133103 in base 4 and 31003 in base 5.

2003 divides 22¹³ - 1.

2003 was the first prime year of the current millennium. The next two are 2011 and 2017.

Source: Number Gossip and Prime Curios!

6661

6661 is a prime number.

6659 and 6661 form a twin prime pair.

6661 is the smallest beastly (containing the string 666) prime number.

6661 and its inversion, 1999, are both primes.

6661 uses only the digits 0, 1, and 5 in bases 6 (50501) and 8 (15005).

6661 has a representation as a sum of two squares: 6661 = 10² + 81².

6661 is the hypotenuse of a primitive Pythagorean triple: 6661² = 1620² + 6461².

Source: Number Gossip

3666

3666 = 2 x 3 x 13 x 47.

3666 is the number of ways to tile a 4 x 46 room with 1 x 2 Tatami mats, with at most three Tatami mats meeting at a point (A068923).

3666 is the number of partitions of the 33rd decimal palindrome into distinct decimal palindromes (A091585).

3666 divides 95⁶ - 1.

Source: OEIS

7070

7070 = 2 x 5 x 7 x 101.

7070 is the number of lines through at least two points of an 8 x 22 grid of points (A160848).

7070 divides 41²⁰ - 1.

7070 is a number n such that n and the square of n use only the digits 0, 4, 7, 8, and 9 (A136959).

Source: OEIS

7837

7837 = 17 x 461.

7837 is the number of primes less than 80000 (A038813).

7837 is a number n such that there are 17 primes between 100n and 100n + 99 (A186509).

7837 is a number n such that 27n + 1 is a square (A219258).

7837 is the smaller of two consecutive lucky numbers with the same digital sum (A118566).

7837 has two representations as a sum of two squares: 7837 = 21² + 86² = 59² + 66².

7837 is the hypotenuse of two primitive Pythagorean triples: 7837² = 875² + 7788² = 3612² + 6955².

7837 divides 48¹⁶ - 1.

Source: OEIS

5110

5110 = 2 x 5 x 7 x 73.

5110 is a multiple of 7 whose digit sum is 7 (A063416).

5110 and the square of 5110 use only the digits 0, 1, 2, 5, and 6 (A136823).

5110 is the number of nonalternating knots with 13 crossings (A051763).

5110 is 21000021 in base 3. It is 7007 in base 9 (A043034).

5110 divides 81³ - 1.

Source: OEIS

9327

9327 = 3 x 3109.

9327 is a value of n for which n and 2n together use each digit 1 to 9 exactly once (A064160).

9327 is a number n such that 2ⁿ + 9 is prime (A057196).

9327 is a number that cannot be written as a sum of three squares.

9327 divides 85²¹ - 1.

Source: What's Special About This Number?

9317

9317 = 7 x 11 x 11 x 11.

9317 is a number n having two distinct prime factors p, q with q = p + 4 (A143203 and A195106).

9317 is a number n with the property that the largest proper divisor of n is a cube (A187104).

9317 is the number of standard Young tableaux with 11 cells and exactly one succession (A238126).

9317 is a number n such that n ends with 7 and is the difference between two cubes in at least one way (A038862).

Source: OEIS

8811

8811 = 3 x 3 x 11 x 89.

8811 is a multiple of 11 containing 11 in its decimal representation (A121031).

8811 is the number of 12 x 12 binary arrays symmetric under horizontal reflection with all ones connected only in a one by five or five by one block (A145065).

8811 divides 34¹² - 1.

Source: OEIS

6395

6395 = 5 x 1279.

6395 is the number of ways to divide a 12 x 12 grid of points into two sets using a straight line (A114043).

6395 is the number of primes of the form 1 + b⁴ for b less than 10⁵ (A215048).

6395 is the number of connected functions on 9 points with a single labeled point (A038002).

Source: What's Special About This Number?

9908

9908 = 2 x 2 x 2477.

9908 is the number of times the digit 2 appears in the first 10⁵ (100,000) digits of pi (A099293).

9908 is the least number that can be expressed as the sum of a prime number and a nonzero square in just 36 different ways (A064283).

9908 is the number of fixed polyominoes with 9 cells (A006762).

9908 is the number of placements of brackets in a monomial of degree 9 in an algebra with two commutative multiplications (A226909).

9908 has a representation as a sum of two squares: 9908 = 38² + 92².

9908 is 304113 in base 5 and 113512 in base 6.

Source: OEIS

2888

2888 = 2 x 2 x 2 x 19 x 19.

2888 is 21212 in base 6.

2888 is the first of five consecutive squareful numbers.

2888 is the smaller of two consecutive numbers divisible by cubes (A068140).

2888 is the smallest multiple of 8 with a digit sum of 26 (A069536).

2888 has a representation as a sum of two identical squares (A001105): 2888 = 38² + 38².

2888 divides 69⁶ - 1.

Source: What's Special About This Number?

5247

5247 = 3 x 3 x 11 x 53.

5247 is the number of ordered ways to write 1 as a sum of reciprocals of integers no larger than 10.

5247 has three 1s and three 3s in its base 4 representation (A045127).

5247 divides 23¹² - 1.

5247 is a number that cannot be written as a sum of three squares.

Source: What's Special About This Number?

8396

8396 = 2 x 2 x 2099.

8396 does not occur in its factorial in base 2 (binary notation) (A093685).

8396 is a number such that it has four 3s in its base 7 representation (A043408).

8396 has four 0s and two 3s in its base 4 representation (A045083).

8396 is the number of 4-bead necklaces labeled with numbers -46 . . . 46 not allowing reversal, with sum zero and first and second differences in -46 . . . 46 (A209008).

Source: What's Special About This Number?

1950

1950 = 2 x 3 x 5 x 5 x 13.

1950 = (144 + 145 + . . . + 156) = (157 + 158 + . . . + 168) (A059270).

1950 is 132132 in base 4, 5454 in base 7, and 3636 in base 8. It is 1166 in base 12 (A033010).

1950 is a number n such that the square of n is the sum of four consecutive primes (A051395).

1950 divides 49⁶ - 1.

1950 is a year with exactly two "Friday the 13ths" (A190652).

Source: What's Special About This Number?

1933

1933 is a prime number.

1931 and 1933 form a twin prime pair.

1933 is centered heptagonal number (A069099).

1933 = (1⁹ + 2⁸ + 3⁷ + 4⁶ + 5⁵)/5.

1933 has a representation as the sum of two squares: 1933 = 13² + 42².

1933 is the hypotenuse of a primitive Pythagorean triple: 1933² = 1092² + 1595².

1933 divides 10²¹ - 1.

Source: Prime Curios!

3626

3626 = 2 x 7 x 7 x 37.

3626 is 24442 in base 6.

3626 is the smallest nonnegative number that is the sum of three squares in exactly 23 ways (A000437).

3626 is a member of the Fibonacci-like sequence beginning with 1 and 9 (A022099).

3626 is the center element of a series of five successive non-squarefree numbers (A188296).

3626 has a representation as a sum of two squares: 3626 = 35² + 49².

3626 divides 31¹² - 1.

Source: What's Special About This Number?

5582

5582 = 2 x 2791.

The sum of the digits of 5582 is the square root of the product of the digits of 5582 (A117720).

5582 is contained as a substring in the 5582nd triangular number (A119238).

5582 is the number of distinct connected monocyclic bipartite graphs with 13 vertices (A214650).

5582 divides 91³ - 1.

Source: OEIS

3442

3442 = 2 x 1721.

3442 is a semiprime with a prime sum of decimal digits and a prime sum of prime factors (A108610).

3442 is exactly between the nearest square and the nearest triangular number (A233074).

3442 is the number of three-dimensional polyominoes with 8 cells (A006766).

3442 has a representation as a sum of two squares: 3442 = 29² + 51².

Source: OEIS

1911

1911 = 3 x 7 x 7 x 13.

1911 is 11101110111 in base 2 (binary) (A023691), 131313 in base 4 (A037576), and 1133 in base 12 (A033010). It is 876 in base 15 and 777 in base 16 (A033029).

1911 is a hendecadonal number (A051682). It is also a heptagonal pyramidal number (A002413).

1911 divides 79³ - 1.

1911 was a year with exactly two "Friday the 13ths" (A190652).

Source: What's Special About This Number?

2637

2637 = 3 x 3 x 293.

2637 is 5115 in base 8.

Deleting the middle two digits of 2637 produces a cube (A217297).

2637 is the number of commutative monoids of order 7 (A058131).

2637 is the sum of nine distinct pentatope numbers (A104399).

2637 has a representation as a sum of two squares: 2637 = 6² + 51².

Source: What's Special About This Number?

5314

5314 = 2 x 2657.

5314 is a semiprime with a prime sum of decimal digits and a prime sum of prime factors (A108610).

5314 is the sum of three consecutive hexagonal numbers (A129109).

5314 has a representation as a sum of two squares: 5314 = 33² + 65².

5314 is the number of positive integers that are not the sum of distinct 40th-order polygonal numbers (A025524).

5314 is a centered 21-gonal number (A069178).

Source: OEIS

9347

9347 = 13 x 719.

9347 is a value of n for which the sum of the square-free divisors of n and n + 1 are the same (A063964).

9347 is a number n such that googol - n is a prime (A108251).

9347 is the number of primes between 46 and 46³ (A117491).

Source: What's Special About This Number?

1902

1902 = 2 x 3 x 317.

1902 has cube that contains only even digits (A052004).

1902 is a number n such that 2n - 1, 4n - 1, and 6n - 1 are primes (A124486).

1902 is the sum of three consecutive semiprimes (A173968).

1902 is the number of primes p such that 8! - p is prime (A140088).

1902 is a year with exactly one "Friday the 13th" (A190651).

Source: What's Special About This Number?

1898

1898 = 2 x 13 x 73.

1898 is 1122 in base 12 (A033010). It is 868 in base 15.

1898 is the smallest multiple of 26 whose digits sum to 26 (A002998).

1898 is the number of primes between 26² and 26³ (A079648).

1898 is the least positive integer that can be represented as the sum of a semiprime and a square in exactly 25 ways (A101181).

1898 has two representations as a sum of two squares: 1898 = 7² + 43² = 23² + 37². It is the sum of two squared primes in exactly two ways (A226539).

1898 divides 81³ - 1.

Source: OEIS

3255

3255 = 3 x 5 x 7 x 31.

3255 is 101010 in base 5 (A033042 and A033115). It is 23023 in base 6. 3255 uses only the digits 0, 1, 2, and 3 in every base up to and including base 7.

3255 is a number that is not the sum of a triangular number, a cube, and a Fibonacci number (A115177).

3255 is a number n such that n - 4, n - 2, n + 2, and n + 4 are prime (A173037).

3255 divides 92⁴ - 1.

Source: OEIS