Properties of the Number 20916

Twenty Thousand Nine Hundred Sixteen

Basics

Value: 20915 → 20916 → 20917

Parity: even

Prime: No

Previous Prime: 20903

Next Prime: 20921

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 2 ² × 3 ² × 7 × 83

Divisors: 1, 2, 3, 4, 6, 7, 9, 12, 14, 18

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101000110110100

Octal: 50664

Duodecimal: 10130

Hexadecimal: 51b4

Square: 437479056

Square Root: 144.6236495183274

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: No

Perfect Number: No

Special

Kaprekar Constant: No

Munchausen Constant: No

Armstrong Number: No

Kaprekar Number: No

Catalan Number: No

Vampire Number: No

Taxicab Number: No

Super Prime: No

Friedman Number: No

Fermat Number: No

Cullen Number: No

OEIS Sequences

Number T(n,k) of n-length words w over a k-ary alphabet {a1, a2, ..., ak} such that #(w,a1) >= #(w,a2) >= ... >= #(w,ak) >= 1, where #(w,x) counts the letters·in word w; triangle T(n,k), n >= 0, 0 <= k <= n, read by rows. A226874

Array read by antidiagonals: T(n,k) is the number of nonisomorphic multisets of permutations of an n-set with k permutations. A362644

Numbers k such that sopfr(k + sopfr(k)) = sopfr(k) + sopfr(sopfr(k)), where sopfr = A001414. A376851

Molien series for complete weight enumerators of self-dual codes over Z/8Z. A92544

Number of n-length words w over a 4-ary alphabet {a1,a2,...,a4} such that #(w,a1) >= #(w,a2) >= ... >= #(w,a4) >= 1, where #(w,x) counts the letters·in word w. A226883

Numbers k such that k and k³ are sums of two twin primes. A213811

Triangle T, read by rows : T(n,k) = A007318(n,k)*A026641(n-k). A171650

Triangle corresponding to the partition array of the M₁ multinomials (A036038). A292222

Terms of A319928 that are congruent to 4 modulo 8: Numbers k == 4 (mod 8) such that there is no other m such that (Z/mZ)* is isomorphic to (Z/kZ)*, where (Z/kZ)* is the multiplicative group of integers modulo k. A372755

a(n) is the least k >= 2 such that (2^k - 1) mod (n·k - 1) = 0. A381923