Properties of the Number 81638

Eighty-One Thousand Six Hundred Thirty-Eight

Basics

Value: 81637 → 81638 → 81639

Parity: even

Prime: No

Previous Prime: 81637

Next Prime: 81647

Digit Sum: 26

Digital Root: 8

Palindrome: No

Factorization: 2 × 40819

Divisors: 1, 2, 40819, 81638

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011111011100110

Octal: 237346

Duodecimal: 3B2B2

Hexadecimal: 13ee6

Square: 6664763044

Square Root: 285.72364270392467

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

Triangle read by rows: T(n,k) = ((Stirling2)²)(n,k) * k! A233357

E.g.f.: (exp(exp(x)-1)-1)². A52896

D'Agapeyeff cipher. A135209

Class 10+ primes. A81638

Number of 4Xn 0..1 arrays avoiding 0 0 1 and 0 1 0 horizontally and 0 1 0 and 1 0 1 vertically. A207520