Properties of the Number 21507

Twenty-One Thousand Five Hundred Seven

Basics

Value: 21506 → 21507 → 21508

Parity: odd

Prime: No

Previous Prime: 21503

Next Prime: 21517

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 67 × 107

Divisors: 1, 3, 67, 107, 201, 321, 7169, 21507

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101010000000011

Octal: 52003

Duodecimal: 10543

Hexadecimal: 5403

Square: 462551049

Square Root: 146.65265084545862

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 perfect squared squares of order n up to symmetries of the square and of its squared subrectangles, if any. A181735

Numbers that are the sum of seven fourth powers in six or more ways. A345572

Numbers that are the sum of seven fourth powers in seven or more ways. A345573

Numbers that are the sum of seven fourth powers in eight or more ways. A345574

Numbers that are the sum of seven fourth powers in exactly eight ways. A345830

Triangle of coefficients of polynomials u(n,x) jointly generated with A210804; see the Formula section. A210803

a(1) = 1; a(n) = ∑_{d∣n, d < n} p(n/d) * a(d), where p = A000041 (partition numbers). A328424

Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 942", based on the 5-celled von Neumann neighborhood. A273797

a(n) = 2·A090495(n) - 1. A274297

Fixed points in A375564. A376584