9900 = 2 x 2 x 3 x 3 x 5 x 5 x 11.
9900 is a pronic number, the product of two consecutive integers: 9900 = 99 x 100.
9900 has two distinct digits in base 2 (10011010101100), base 10 (9900), base 19 (1881), and base 21 (1199), each using two digits the same number of times.
9900 divides 1910 - 1.
Source: Number Gossip
Tuesday, September 30, 2014
Monday, September 29, 2014
Friday, September 26, 2014
5873
5873 = 7 x 839.
5873 divides 11 + 22 + 33 + . . . + 58735873 (A128981).
5873 is a number n such that n divides the sum of the first n numbers from Flavius Josephus's sieve (A218665).
Source: What's Special About This Number?
5873 divides 11 + 22 + 33 + . . . + 58735873 (A128981).
5873 is a number n such that n divides the sum of the first n numbers from Flavius Josephus's sieve (A218665).
Source: What's Special About This Number?
Thursday, September 25, 2014
1825
1825 = 5 x 5 x 73.
1825 is an octagonal number (A000567).
1825 is the smallest number whose square begins with three 3s (A131573 and A025286 and A025304 and A034982).
1825 has three representations as a sum of two squares (A025313): 1825 = 122 + 412 = 152 + 402 = 232 + 362.
1825 is the hypotenuse of two primitive Pythagorean triples: 18252 = 7672 + 16562 = 9842 + 15372.
1825 divides 742 - 1.
Source: What's Special About This Number?
1825 is an octagonal number (A000567).
1825 is the smallest number whose square begins with three 3s (A131573 and A025286 and A025304 and A034982).
1825 has three representations as a sum of two squares (A025313): 1825 = 122 + 412 = 152 + 402 = 232 + 362.
1825 is the hypotenuse of two primitive Pythagorean triples: 18252 = 7672 + 16562 = 9842 + 15372.
1825 divides 742 - 1.
Source: What's Special About This Number?
Wednesday, September 24, 2014
4320
4320 = 2 x 2 x 2 x 2 x 2 x 3 x 3 x 3 x 5.
4320 = (6 + 4) x (6 + 3) x (6 + 2) x (6 + 0).
4320 = 7! - 6! (A001563 and A058295).
4320 is the maximal kissing number of a 16-dimensional laminated lattice (A002336).
4320 is a number n such that n! is the product of exactly four smaller factorials (A109097).
4320 divides 538 - 1.
Source: OEIS
4320 = (6 + 4) x (6 + 3) x (6 + 2) x (6 + 0).
4320 = 7! - 6! (A001563 and A058295).
4320 is the maximal kissing number of a 16-dimensional laminated lattice (A002336).
4320 is a number n such that n! is the product of exactly four smaller factorials (A109097).
4320 divides 538 - 1.
Source: OEIS
Tuesday, September 23, 2014
Monday, September 22, 2014
5545
5545 = 5 x 1109.
5545 is a member of the Fibonacci-type sequence starting with 1 and 5 (A022095).
5545 uses only the digits 1 and 2 in base 4 (1112221) and base 7 (22111).
5545 is a concentric dodecagonal number (A195143).
5545 has two representations as a sum of two squares: 5545 = 192 + 722 = 282 + 692.
5545 is the hypotenuse of two primitive Pythagorean triples: 55452 = 27362 + 48232 = 38642 + 39772.
Source: What's Special About This Number?
5545 is a member of the Fibonacci-type sequence starting with 1 and 5 (A022095).
5545 uses only the digits 1 and 2 in base 4 (1112221) and base 7 (22111).
5545 is a concentric dodecagonal number (A195143).
5545 has two representations as a sum of two squares: 5545 = 192 + 722 = 282 + 692.
5545 is the hypotenuse of two primitive Pythagorean triples: 55452 = 27362 + 48232 = 38642 + 39772.
Source: What's Special About This Number?
Friday, September 19, 2014
5276
5276 = 2 x 2 x 1319.
5276 is the number of binary strings of length 14 with no substrings equal to 0000 or 0010 (A164387).
5276 is a number n such that n - 3, n + 3, and n + 5 are all primes (A144842).
5276 is the number of moves needed to solve the 4-peg Tower of Hanoi puzzle with 22 disks (A160002).
5276 cannot be written as a sum of three squares.
Source: OEIS
5276 is the number of binary strings of length 14 with no substrings equal to 0000 or 0010 (A164387).
5276 is a number n such that n - 3, n + 3, and n + 5 are all primes (A144842).
5276 is the number of moves needed to solve the 4-peg Tower of Hanoi puzzle with 22 disks (A160002).
5276 cannot be written as a sum of three squares.
Source: OEIS
Thursday, September 18, 2014
1796
1796 = 2 x 2 x 449.
1796 is the palindrome 2110112 in base 3 (A043002).
1796 is the number of lines through exactly 10 points of a 52 x 52 grid of points (A018817).
1796 is the sum of 11 nonzero 8th powers (A003389).
1796 has a representation as a sum of two squares: 1796 = 142 + 402.
1796 divides 674 - 1.
In the year 1796, Carl Friedrich Gauss proved that a regular 17-gon can be constructed using only compass and straightedge.
Source: OEIS
1796 is the palindrome 2110112 in base 3 (A043002).
1796 is the number of lines through exactly 10 points of a 52 x 52 grid of points (A018817).
1796 is the sum of 11 nonzero 8th powers (A003389).
1796 has a representation as a sum of two squares: 1796 = 142 + 402.
1796 divides 674 - 1.
In the year 1796, Carl Friedrich Gauss proved that a regular 17-gon can be constructed using only compass and straightedge.
Source: OEIS
Wednesday, September 17, 2014
3810
3810 = 2 x 3 x 5 x 127.
3810 is the number of ways to place a non-attacking white and black pawn on a 9 x 9 chessboard (A035290).
3810 is a sum of primes between successive pairs of twin primes (A078731).
3810 in base 6 and base 9 both use the same set of digits {0, 2, 3, 5} (A037436).
3810 divides 196 - 1.
Source: What's Special About This Number?
3810 is the number of ways to place a non-attacking white and black pawn on a 9 x 9 chessboard (A035290).
3810 is a sum of primes between successive pairs of twin primes (A078731).
3810 in base 6 and base 9 both use the same set of digits {0, 2, 3, 5} (A037436).
3810 divides 196 - 1.
Source: What's Special About This Number?
Tuesday, September 16, 2014
9931
9931 is a prime number.
9929 and 9931 form a twin prime pair. 9931 is the larger of the greatest twin prime pair with four digits (A114429).
9931 and its reversal, 1399, are both primes (A101782).
9931 is a prime with 10 as the smallest positive primitive root (A061323).
9931 is a prime p such that p - 2 and p3 - 2 are also prime (A240124).
9931 is a prime that is the sum of 8 but no fewer squared primes (A183216).
Source: OEIS
9929 and 9931 form a twin prime pair. 9931 is the larger of the greatest twin prime pair with four digits (A114429).
9931 and its reversal, 1399, are both primes (A101782).
9931 is a prime with 10 as the smallest positive primitive root (A061323).
9931 is a prime p such that p - 2 and p3 - 2 are also prime (A240124).
9931 is a prime that is the sum of 8 but no fewer squared primes (A183216).
Source: OEIS
Monday, September 15, 2014
Friday, September 12, 2014
Thursday, September 11, 2014
6233
6233 = 23 x 271.
6233 is the least number that can be expressed as the sum of a prime number and a nonzero square in just 28 ways (A064283).
6233 is 22112212 in base 3. It is 144413 in base 5 and 14131 in base 8. 6233 is 8485 in base 9.
6233, 623, 62, and 6 are all semiprimes (A085733).
6233 is the number of primes of the form x2 + 1 less than 233 (A083847).
Source: OEIS
6233 is the least number that can be expressed as the sum of a prime number and a nonzero square in just 28 ways (A064283).
6233 is 22112212 in base 3. It is 144413 in base 5 and 14131 in base 8. 6233 is 8485 in base 9.
6233, 623, 62, and 6 are all semiprimes (A085733).
6233 is the number of primes of the form x2 + 1 less than 233 (A083847).
Source: OEIS
Wednesday, September 10, 2014
1793
1793 = 11 x 163.
1793, 1795, 1797. and 1799 are all semiprimes (A092126).
1793 is a pentanacci number (A001591).
1793 is the sum of three distinct cubes in two or more ways (A024974).
1793 is the number of tilings of a 2 x 8 board wth 1 x 1 and L-shaped tiles (where the L-shaped tiles cover 3 squares) (A127864).
1793 is a number such that its digit sum in base 2 and its digit sum in base 10 is in the ratio of 2:10 (A135110).
1793 divides 5815 - 1.
Source: What's Special About This Number?
1793, 1795, 1797. and 1799 are all semiprimes (A092126).
1793 is a pentanacci number (A001591).
1793 is the sum of three distinct cubes in two or more ways (A024974).
1793 is the number of tilings of a 2 x 8 board wth 1 x 1 and L-shaped tiles (where the L-shaped tiles cover 3 squares) (A127864).
1793 is a number such that its digit sum in base 2 and its digit sum in base 10 is in the ratio of 2:10 (A135110).
1793 divides 5815 - 1.
Source: What's Special About This Number?
Tuesday, September 9, 2014
Monday, September 8, 2014
Friday, September 5, 2014
4220
4220 = 2 x 5 x 211.
4220 is a number n for which the sum of the first n composite numbers is a palindrome (A053779).
4220 is the maximum number of regions the plane is divided into by 38 triangles (A077588).
4220 is the number of binary rooted trees with 39 nodes and internal path length 39 (A108643).
4220 divides 7110 - 1.
Source: What's Special About This Number?
4220 is a number n for which the sum of the first n composite numbers is a palindrome (A053779).
4220 is the maximum number of regions the plane is divided into by 38 triangles (A077588).
4220 is the number of binary rooted trees with 39 nodes and internal path length 39 (A108643).
4220 divides 7110 - 1.
Source: What's Special About This Number?
Thursday, September 4, 2014
5940
5940 = 2 x 2 x 3 x 3 x 3 x 5 x 11.
5940 is divisible by its reverse, 495 (A223080).
5940 = (9 x 10 x 11 x 12)/2 (A033486).
5940 is 2244 in base 14 (A035012).
5940 is the sum of the interior angles (in degrees) of a 35-sided polygon (A066164).
5940 divides 896 - 1.
Source: What's Special About This Number?
5940 is divisible by its reverse, 495 (A223080).
5940 = (9 x 10 x 11 x 12)/2 (A033486).
5940 is 2244 in base 14 (A035012).
5940 is the sum of the interior angles (in degrees) of a 35-sided polygon (A066164).
5940 divides 896 - 1.
Source: What's Special About This Number?
Wednesday, September 3, 2014
4546
4546 = 2 x 2273.
The number 4546 and its prime factors use each of the digits from 2 to 7 (A058760).
4546 is a member of the sequence in which each term is the sum of the previous term and the square of the term before that (A000278).
4546 has a representation as a sum of two squares: 4546 = 392 + 552.
Source: OEIS
The number 4546 and its prime factors use each of the digits from 2 to 7 (A058760).
4546 is a member of the sequence in which each term is the sum of the previous term and the square of the term before that (A000278).
4546 has a representation as a sum of two squares: 4546 = 392 + 552.
Source: OEIS
Tuesday, September 2, 2014
2708
2708 = 2 x 2 x 677.
2708 in base 6 has digits in the order 2, 0, 3, 1, then repeats 2 (A037725).
2708 in base 2 has exactly 10 runs (A043577): 101010010100.
2708 is a number n such that the three numbers n - 1, n + 3, and n + 5 are all prime (A144840).
2708 has a representation as a sum of two squares: 2708 = 22 + 522.
2708 is the number of partitions of 84 into distinct parts, where the difference between the number of odd parts and the number of even parts is 5 (A240141).
Source: OEIS
2708 in base 6 has digits in the order 2, 0, 3, 1, then repeats 2 (A037725).
2708 in base 2 has exactly 10 runs (A043577): 101010010100.
2708 is a number n such that the three numbers n - 1, n + 3, and n + 5 are all prime (A144840).
2708 has a representation as a sum of two squares: 2708 = 22 + 522.
2708 is the number of partitions of 84 into distinct parts, where the difference between the number of odd parts and the number of even parts is 5 (A240141).
Source: OEIS