Properties of the Number 21750

Twenty-One Thousand Seven Hundred Fifty

Basics

Value: 21749 → 21750 → 21751

Parity: even

Prime: No

Previous Prime: 21739

Next Prime: 21751

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 2 × 3 × 5 ³ × 29

Divisors: 1, 2, 3, 5, 6, 10, 15, 25, 29, 30

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010011110110

Octal: 52366

Duodecimal: 10706

Hexadecimal: 54f6

Square: 473062500

Square Root: 147.47881203752627

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 of ways to write n as an ordered sum of 6 primes (counting 1 as a prime). A341985

a(0) = 1; a(n) = ∑_k=0..n-1 binomial(k+6,6) * binomial(n-1,k) * a(k) * a(n-1-k). A385948

Expansion of ∏_m>=1 (1 + m·q^m)^-4. A22696

Number of (w,x,y,z) with all terms in {0,...,n} and (least gapsize)=1. A212894

Expansion of f(-x)² * f(-x¹⁰) / φ(-x)³ in powers of·where φ(), f() are Ramanujan θ functions. A262050

Degrees of irreducible representations of Rudvalis group Ru. A3918

a(1)=2³*5·7*29=8120; for n>1, a(n) = (-1)σ(a(n-1)). A126602

a(n) = ∑_d∣n A007955(d) * A008683(n/d) = ∑_d∣n A007955(d) * μ(n/d), where A007955(m) = number of divisors of m. A174940

a(n) = (n/2) * (n³ - 2·n² - 2·n + 5). A242983

G.f. A(x) satisfies: ∑_k=0..n [x^k] A(x)ⁿ = binomial(7·n,2·n). A244653