Properties of the Number 81680

Eighty-One Thousand Six Hundred Eighty

Basics

Value: 81679 → 81680 → 81681

Parity: even

Prime: No

Previous Prime: 81677

Next Prime: 81689

Digit Sum: 23

Digital Root: 5

Palindrome: No

Factorization: 2 ⁴ × 5 × 1021

Divisors: 1, 2, 4, 5, 8, 10, 16, 20, 40, 80

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011111100010000

Octal: 237420

Duodecimal: 3B328

Hexadecimal: 13f10

Square: 6671622400

Square Root: 285.79713084634

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

Expansion of e.g.f. exp( (sin(x) + x·cos(x))/2 ). A349103

Number of (n+2) X (6+2) 0..1 arrays with no 3·3 subblock diagonal sum 0 and no antidiagonal sum 3 and no row sum 1 and no column sum 1. A257445

a(n) = (7ⁿ - 6ⁿ - 5ⁿ - 4ⁿ + 4·3ⁿ)/2. A81680