Properties of the Number 21312

Twenty-One Thousand Three Hundred Twelve

Basics

Value: 21311 → 21312 → 21313

Parity: even

Prime: No

Previous Prime: 21283

Next Prime: 21313

Digit Sum: 9

Digital Root: 9

Palindrome: Yes

Factorization: 2 ⁶ × 3 ² × 37

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

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101001101000000

Octal: 51500

Duodecimal: 10400

Hexadecimal: 5340

Square: 454201344

Square Root: 145.98630072715727

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 of writing n as a sum of 8 squares. A143

Fourier coefficients of E_0,4. A35016

Rhonda numbers in sexagesimal number system. A255731

T(n,k)=Number of (n+1)X(k+1) arrays of permutations of 0..(n+1)*(k+1)-1 with each element having directed index change 1,0 0,-1 1,2 or -1,1. A264583

Palindromic and divisible by 8. A45643

Palindromic and divisible by 9. A45644

θ series of {D₈}* lattice. A8427

Palindromes that are divisible by 6. A45641

a(1) = 3, a(n) = smallest nontrivial palindromic multiple of a(n-1). a(n) is not equal to a(n-1) or a concatenation of a(n-1) with itself. A83149

a(0) = 1; for n>0, a(n) = 16 times sum of cubes of divisors of n. A92820