Properties of the Number 21320

Twenty-One Thousand Three Hundred Twenty

Basics

Value: 21319 → 21320 → 21321

Parity: even

Prime: No

Previous Prime: 21319

Next Prime: 21323

Digit Sum: 8

Digital Root: 8

Palindrome: No

Factorization: 2 ³ × 5 × 13 × 41

Divisors: 1, 2, 4, 5, 8, 10, 13, 20, 26, 40

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001101001000

Octal: 51510

Duodecimal: 10408

Hexadecimal: 5348

Square: 454542400

Square Root: 146.01369798755184

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

a(n) = 2·binomial(n,3). A7290

Number of "cubic partitions" of n: expansion of ∏_k>0 1/((1-x^2k)²*(1-x^2k-1)) in powers of x. A2513

Numbers k such that the largest unitary divisor of σ(k) that is coprime with A003961(k) is also a unitary divisor of k. A351551

Lexicographically earliest sequence of nonnegative integers such that two distinct terms differ by at least 4 decimal digits. A346000

a(1) = 1, a(2) = 2, a(3) = 3, a(n+3) = a(n) + a(n+1). A84338

a(n) = 2·A000447(n). A259110

a(n) = the product of numbers k such that σ(k) = σ(n). A325653

Expansion of (1-x)/(1+2·x+x²+x³). A78065

Diagonal sums of Riordan array (1-x-x²,x(1-x)). A109266

A triangular array distributing the values of sequence A072213 (cf. A115994). A128626