Properties of the Number 81321

Eighty-One Thousand Three Hundred Twenty-One

Basics

Value: 81320 → 81321 → 81322

Parity: odd

Prime: No

Previous Prime: 81307

Next Prime: 81331

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 27107

Divisors: 1, 3, 27107, 81321

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011110110101001

Octal: 236651

Duodecimal: 3B089

Hexadecimal: 13da9

Square: 6613105041

Square Root: 285.1683713177182

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

Integers k such that 2047·2^k - 1 is prime. A387927

Column 2 of triangle A113993, also equals column 0 of A113983³. A113994

a(n) = (2/3)*(2·n+1)*(2·n-1)!*binomial(3·n,2·n). A81321