Properties of the Number 81864

Eighty-One Thousand Eight Hundred Sixty-Four

Basics

Value: 81863 → 81864 → 81865

Parity: even

Prime: No

Previous Prime: 81853

Next Prime: 81869

Digit Sum: 27

Digital Root: 9

Palindrome: No

Factorization: 2 ³ × 3 ³ × 379

Divisors: 1, 2, 3, 4, 6, 8, 9, 12, 18, 24

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 10011111111001000

Octal: 237710

Duodecimal: 3B460

Hexadecimal: 13fc8

Square: 6701714496

Square Root: 286.11885642159274

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

T(n,k) = number of (n+1) X (k+1) 0..3 arrays with no 2 X 2 subblock having the number of clockwise edge increases equal to the number of counterclockwise edge increases in its adjacent leftward or upward neighbors. A205944

If n mod 2 = 0 then a(n) = n⁴/4 - 2·n² + 3·n; otherwise, a(n) = n⁴/4 - 2·n² + 3·n - 5/4. A64835

a(0)=1, a(1)=8, a(n)=17·a(n-1)-64·a(n-2) for n>1. A165323

a(n) = [xⁿ] 1/(1 - n·x/(1 - n·x²/(1 - n·x³/(1 - n·x⁴/(1 - n·x⁵/(1 - ...)))))), a continued fraction. A291274

Number of (n+1) X 3 0..3 arrays with no 2 X 2 subblock having the number of clockwise edge increases equal to the number of counterclockwise edge increases in its adjacent leftward or upward neighbors. A205938

Number of (n+1) X 4 0..3 arrays with no 2 X 2 subblock having the number of clockwise edge increases equal to the number of counterclockwise edge increases in its adjacent leftward or upward neighbors. A205939

Number of 4-cycles in the n-cycle complement and (n+1)-wheel complement graph. A367985

Sum of 5th powers of the divisors of odd numbers: a(n) = sigma₅(2n-1). A81864