## Monday, March 31, 2014

### 9727

9727 = 71 x 137.

9727 is 302402 in base 5.

9727 divides 7217 - 1.

9727 is a number that cannot be written as the sum of three squares.

13 x 97272 + 13 x 9727 + 1 is a square (A104240).

Source: OEIS

## Friday, March 28, 2014

### 8361

8361 = 3 x 3 x 929.

8361 is a Leyland number (A076980).

8361 is a number of form 2n + n2 for n = 13 (A001580).

The sum of the divisors of 8361 and the number of divisors of 8361 are both triangular numbers (A070996).

8361 is the sum of exactly two sets of Fibonacci numbers (A122194).

8361 has a representation as a sum of two squares: 8361 = 602 + 692.

8361 divides 4616 - 1.

## Thursday, March 27, 2014

### 9645

9645 = 3 x 5 x 643.

9645 is 302040 in base 5. It is 22655 in base 8.

9645 is the number of partitions of 50 such that (greatest part) - (least part) = number of parts (A237832).

9645 is a member of the sequence in which the next term is the sum of the previous term and the square of the sum of its decimal digits, starting with 10 (A112787).

Source: OEIS

## Wednesday, March 26, 2014

### 1997

1997 is a prime number.

1997 and 1999 form a twin prime pair.

The 1997 substrings 199 and 997 are also primes (A069489).

1997 remains a prime when a single digit 9 is inserted between any two consecutive digits or as the leading or trailing digit (A215421).

1997 is a prime factor of 87654321.

1997 has a representation as a sum of two squares: 1997 = 292 + 342.

1997 is the hypotenuse of a primitive Pythagorean triple: 19972 = 3152 + 19722.

## Tuesday, March 25, 2014

### 1959

1959 = 3 x 653.

1959 is 132213 in base 4. It is 13023 in base 6.

1959 is a number n such that n1n and 1n1 are both prime (195911959 and 119591) (A090262).

1959 is the least value of n such that 51n contains only the digits 0 and 9 (A096688).

1959 is the largest integer that cannot be written as the sum of squares of integers larger than 17 (A193018).

1959 is the number of 2 x 2 integer matrices with entries from {0, 1, 2, ..., 40} having determinant 1 (A171503).

1959 was a year with exactly three "Friday the 13ths" (A190653).

Source: OEIS

## Monday, March 24, 2014

### 2828

2828 = 2 x 2 x 7 x 101.

2828 is a value of n such that n(n + 8) is a palindrome (A028567): 2828 x 2836 = 8020208.

2828 is the number of lines that pass through exactly three points of an 18 x 18 grid of points (A018810).

2828 is the number of tatami tilings of a 6 x 9 grid (with monomers allowed) (A192092).

2828 is the sum of seven positive 7th powers (A003374): 2828 = 37 + 27 + 27 + 27 + 27 + 27 + 17.

2828 divides 4120 - 1.

## Friday, March 21, 2014

### 4410

4410 = 2 x 3 x 3 x 5 x 7 x 7.

4410 is a Padovan number (A000931).

4410 is 120120 in base 5.

4410 is a concentric decagonal number (A195142).

4410 is the smallest sum of 42 consecutive odd primes that is a multiple of 42 (A132810).

4410 has a representation as a sum of two squares: 4410 = 212 + 632.

4410 divides 196 - 1.

## Thursday, March 20, 2014

### 1922

1922 = 2 x 31 x 31.

1922 has a representation as a sum of two squares (A081324): 1922 = 312 + 312.

1992 in base 5 contains each of the digits from 0 to 4 once: 30142.

1992 is the maximum number of regions into which the plane can be divided using 16 (concave) quadrilaterals (A077591).

1922 plus the sum of its digits (14) equals a square (A066564): 1922 + 14 = 1936 = 442.

1992 is the sum of distinct nonzero 4th powers (A003999): 1922 = 64 + 54 + 14.

1922 was a year with exactly two "Friday the 13ths" (A190652).

Source: OEIS

## Wednesday, March 19, 2014

### 2576

2576 = 2 x 2 x 2 x 2 x 7 x 23.

2576 has exactly the same digits in three different bases: 40301 in base 5, 10340 in base 7, and 00431 in base 25.

2576 is the number of ways of writing 72 as a sum of eight nonnegative cubes (A173681).

2576 is the number of ways to place a non-attacking white and black queen on an 8 x 8 chessboard (A035291).

2576 divides 476 - 1.

## Tuesday, March 18, 2014

### 9416

9416 = 2 x 2 x 2 x 11 x 107.

9416 is a value of n for which n and 8n (75328) together use each digit from 1 to 9 exactly once.

9416 uses only the digits 0, 1, 2, and 3 in bases 2, 3, 4, 5, 6, and 8.

9416 is the number of anisohedral polyiamonds with 29 cells (A075224).

9416 is the number of partitions of 42 in which each part occurs an odd number (or zero) times (A055922).

9416 is the number of primes of the form x8 + 1 less than 1045 (A214454).

## Monday, March 17, 2014

### 1889

1889 is a prime number. It is a Sophie Germain prime because 2 x 1889 + 1= 3779 is also prime (A005384).

1889 is the smallest prime such that it and the next four primes (1889, 1901, 1907, 1913, and 1931) are all 5(mod 6), that is, leave a remainder of 5 when divided by 6.

1889 is the smallest prime with digit sum 26 (A067180).

1889 and 118891 are both primes (A069687).

1889 has a representation as a sum of two squares: 1889 = 172 + 402.

1889 is the hypotenuse of a primitive Pythagorean triple: 18892 = 13112 + 13602.

1889 is a divisor of 858 - 1.

The Wall Street Journal was first published in the year 1889.

Source: Prime Curios!

## Friday, March 14, 2014

### 9201

9201 = 3 x 3067.

9201 is a semiprime equidistant from and between the primes 9199 and 9203 (A125215).

9201 is palindromic in base 2 (binary): 10001111110001. It is 35553 in base 7 (A182234).

9201 is a truncated octahedral number (A005910).

5201 is a number n such that n6 +/- 2 are primes (A154938).

## Thursday, March 13, 2014

### 5503

5503 is a prime number.

5501 and 5503 form a twin prime pair.

5503 is 1111333 in base 4 (A045132).

5503 is a prime whose base 7 representation (22021) also is the base 3 representation of a prime (223) (A235470).

5503 is a member of the Fibonacci-like sequence beginning with 1 and 23 (A022393).

The cube of 5503 contains each of the digits from 1 to 9 but not 0 (A124628): 55033 = 166,647,398,527.

Source: OEIS

## Wednesday, March 12, 2014

### 9957

9957 = 3 x 3319.

9957 uses the digits 0, 1, 3, and 4 in bases 6 (114033) and 7 (41013).

9957 is the number of homeomorphically irreducible general graphs on 6 labeled nodes and with 5 edges (A060581).

9957 Raffaellosanti is a main-belt asteroid discovered in 1991 and named for Raffaello Sanzio (Raphael), a master of the Italian Renaissance.

Source: OEIS

## Tuesday, March 11, 2014

### 1860

1860 = 2 x 2 x 3 x 5 x 31.

1860 is the number of ways to 12-color the faces of a tetrahedron (A006008).

1860 uses each of the digits from 0 to 4 once in its representation in base 6 (12340). It is 1441 in base 11.

1860 is equal to the sum of the squares of its first 11 divisors (A185584): 1860 = 12 + 22 + 32 + 42 + 52 + 62 + 102 + 122 + 152 + 202 + 302.

1860 divides 612 - 1.

1860 is a year that had five Wednesdays in the month of February (A141039).

## Monday, March 10, 2014

### 1844

1844 = 2 x 2 x 461.

1844 is a number of the form 3n - n3 for n = 7 (A024026).

1844 is the sum of ten nonzero 6th powers (A003366).

1844 has a representation as a sum of two squares: 1844 = 202 + 382.

1844 divides 9310 - 1.

1884 is the number of hands of 6 cards containing a straight flush (A143314).

1844 is a year that has five Thursdays in the month of February (A143995).

Source: OEIS

## Friday, March 7, 2014

### 1826

1826 = 2 x 11 x 83.

The sum of the prime factors of 1826 is equal to product of its digits: 2 + 11 + 83 = 1 x 8 x 2 x 6 = 96.

1826 uses each of the digits from 0 to 4 once in base 5 (24301). It is 2448 in base 9.

1826 is the sum of the third powers of four consecutive primes (A133525): 1826 = 113 + 73 + 53 + 33.

1826 is a decagonal pyramidal number (A007585).

1826 is a number whose square (3334276) starts with three identical digits (A131573).

## Thursday, March 6, 2014

### 6718

6718 = 2 x 3359.

There are 6718 digits in the binary representation of the 26th prime Fibonacci number (A215367).

The sum of the 6718th and 6719th primes is a square (A109311).

The distinct consecutive digits 6718 appear in the decimal expansion of the square root of 2 (A167834).

6718 is the number of 2-anisohedral polyhexes of order 17 (A120117).

Source: On-Line Encyclopedia of Integer Sequences

## Wednesday, March 5, 2014

### 6611

6611 = 11 x 601.

6611 is a value of n such that the nth Cullen number is prime (A005849).

6611 is the number of primes between 3,400,000 and 3,500,000 (A038825).

6611 is a potential magic constant of 9 x 9 magic squares composed of consecutive primes (A191679).

6611 divides 3210 - 1. It is also a divisor of 250 - 1 (A003554).

## Tuesday, March 4, 2014

### 7437

7437 = 3 x 37 x 67.

7437 divides 684 - 1.

7437 arises in the sequence that starts with 1013, repeatedly reversing the digits and adding 2 to get the next term (A120214).

The Elevation Beer Co. is Colorado microbrewery that produced Elevation 7437 Double IPA for its first anniversary in 2013.

Source: On-Line Encyclopedia of Integer Sequences

## Monday, March 3, 2014

### 8285

8285 = 5 x 1657.

8285 is the rounded volume of a regular octahedron with edge length 26 (A071400).

In base 4 8285 and the square of 8285 contain the same digits in the same proportion (A061658): 2001131 and 10011312013012.

8285 has two representations as a sum of two squares: 8285 = 22 + 912 = 532 + 742.

8285 is the hypotenuse of two primitive Pythagorean triples: 82852 = 3642 + 82772 = 26672 + 78442.

8285 divides 716 - 1.

Source: On-Line Encyclopedia of Integer Sequences