Properties of the Number 81221

Eighty-One Thousand Two Hundred Twenty-One

Basics

Value: 81220 → 81221 → 81222

Parity: odd

Prime: No

Previous Prime: 81203

Next Prime: 81223

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 7 × 41 × 283

Divisors: 1, 7, 41, 283, 287, 1981, 11603, 81221

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011110101000101

Octal: 236505

Duodecimal: 3B005

Hexadecimal: 13d45

Square: 6596850841

Square Root: 284.99298236974187

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

9-gonal (or enneagonal) pyramidal numbers: a(n) = n*(n+1)*(7·n-4)/6. A7584

a(n) = 100·n² + 100·n + 21. A152161

Odd 9-gonal (nonagonal) pyramidal numbers. A218328

a(n) = (8·n+3)*(8·n+7). A146301

Number of consecutive numbers >= n having at least one square divisor > 1. A81221