Properties of the Number 21744

Twenty-One Thousand Seven Hundred Forty-Four

Basics

Value: 21743 → 21744 → 21745

Parity: even

Prime: No

Previous Prime: 21739

Next Prime: 21751

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 2 ⁴ × 3 ² × 151

Divisors: 1, 2, 3, 4, 6, 8, 9, 12, 16, 18

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010011110000

Octal: 52360

Duodecimal: 10700

Hexadecimal: 54f0

Square: 472801536

Square Root: 147.4584687293341

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

Expansion of (1+2·x+3·x²)/((1-x)³*(1-x²)). A55232

a(n) = ∑_k=3..n binomial(k,3) * floor(n/k). A366971

Maximum detour index of any bipartite graph on n nodes. A296819

Detour index of the n X n grid graph. A296779

Expansion of ( ∑_k>=0 k² * q^k² )⁴. A347803

Number of 4 X n (0,1) matrices such that each row and each column is nondecreasing or nonincreasing. A86114

a(n) = 2ⁿ for n = 0..4; for n > 4, a(n) = 2·a(n-1) + a(n-5). A98588

Riordan array ((1-x)/(1-3·x), x*(1-x)/(1-3·x)). A125693

a(1)=1, a(n) = a(n-1) + n⁵ if n odd, a(n) = a(n-1) + n⁴ if n is even. A135214

Detour index for the n X n torus grid graph. A296784