Properties of the Number 81745

Eighty-One Thousand Seven Hundred Forty-Five

Basics

Value: 81744 → 81745 → 81746

Parity: odd

Prime: No

Previous Prime: 81737

Next Prime: 81749

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 5 × 16349

Divisors: 1, 5, 16349, 81745

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 10011111101010001

Octal: 237521

Duodecimal: 3B381

Hexadecimal: 13f51

Square: 6682245025

Square Root: 285.91082525850607

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

Constant term of the reduction by x² -> x+1 of the polynomial p(n,x) defined at Comments. A192981

Number of edge-connected components of polygonal cells in the pinwheel tiling up to rotation of the tiling. A385265

Number of 5-step one space for components leftwards or up, two space for components rightwards or down asymmetric quasi-bishop's tours (antidiagonal moves become knight moves) on an n X n board summed over all starting positions. A187609

a(n) = 2·a(n-1) + a(n-2) - [a(n-2)/2] - [a(n-4)/2] - [a(n-5)/2] where [k] := floor(k). A173514

a(n) = A080901(n) - n. A81745