Properties of the Number 81859

Eighty-One Thousand Eight Hundred Fifty-Nine

Basics

Value: 81858 → 81859 → 81860

Parity: odd

Prime: No

Previous Prime: 81853

Next Prime: 81869

Digit Sum: 31

Digital Root: 4

Palindrome: No

Factorization: 109 × 751

Divisors: 1, 109, 751, 81859

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

4823 Try Today's Challenge

Representations

Binary: 10011111111000011

Octal: 237703

Duodecimal: 3B457

Hexadecimal: 13fc3

Square: 6700895881

Square Root: 286.1101186606304

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

Number of nonempty subsequences {s(k)} of 1..n such that the difference sequence is palindromic. A53599

a(n) = 5·2ⁿ - 4·n - 5. A126284

a(n) = a(n-1) - a(n-2) + a(n-3) + a(n-4), with a(1) = a(2) = a(3) = a(4) = 1. A343885

Short leg of primitive Pythagorean triangles sorted on semiperimeter. A81859

Triangle read by rows: T(n,k) is the number of permutations p of [n] such that the number of inversions of the word formed by the leading entries of the blocks of p is k. A block of a permutation is a maximal sequence of consecutive integers which appear in consecutive positions. For example, the permutation 5412367 has 4 blocks: 5, 4, 123, and 67; their leading entries are 5,4,1, and 6 and the word 5416 has 3 inversions. A186372