Properties of the Number 21065

Twenty-One Thousand Sixty-Five

Basics

Value: 21064 → 21065 → 21066

Parity: odd

Prime: No

Previous Prime: 21061

Next Prime: 21067

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 5 × 11 × 383

Divisors: 1, 5, 11, 55, 383, 1915, 4213, 21065

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001001001001

Octal: 51111

Duodecimal: 10235

Hexadecimal: 5249

Square: 443734225

Square Root: 145.13786549346796

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 G(n,k) of set partitions of {1,...,n} into sets of size at most k; triangle G(n,k), n>=0, 0<=k<=n, read by rows. A229223

Number of squares on infinite chessboard at <= n knight's moves from a fixed square. A18836

a(n) = T(n,n-6), array T as in A055801. A55806

The partition function G(n,6). A148092

a(n) = ∑_{k=0..floor(n/2)} binomial(3·n-k,n-2·k). A371742

Antidiagonal sums of A175105. A179807

a(n) = T(n, 2·n-6), T given by A027926. A27929

(Sum of composites among next n numbers)-(sum of primes among next n numbers). A94338

Numbers having four 1's in base 8. A43428

Decimal expansion of 1/61. A21065