Properties of the Number 81664

Eighty-One Thousand Six Hundred Sixty-Four

Basics

Value: 81663 → 81664 → 81665

Parity: even

Prime: No

Previous Prime: 81649

Next Prime: 81667

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 2 ⁸ × 11 × 29

Divisors: 1, 2, 4, 8, 11, 16, 22, 29, 32, 44

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 10011111100000000

Octal: 237400

Duodecimal: 3B314

Hexadecimal: 13f00

Square: 6669008896

Square Root: 285.769137591868

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

Numbers n such that n divides the (left) concatenation of all numbers <= n written in base 25 (most significant digit on right). A61978

T(n,k)=Number of length n+2 0..k arrays with the medians of every three consecutive terms nondecreasing. A250140

Number of permutations of length 2·n-1 with no local maxima in even positions. A113583

Number of 2-color vertex orderings of the labeled path graph on n vertices in which the number 1 is assigned to a vertex in an odd position. A360514

Decimal representation of the diagonal from the origin to the corner of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 169", based on the 5-celled von Neumann neighborhood. A286174

Glaisher's function G(n) (18 squares version). A2609

Number of singly defective permutations of 1..n with exactly 1 maximum. A183264

a(n) = A218542(n) - A218543(n). A257259

Number of permutations of [1..n] which achieve the worse case bound for a graph domination problem. A272640

Inverse Euler transform of Thue-Morse sequence A001285. A316149