Properties of the Number 81620

Eighty-One Thousand Six Hundred Twenty

Basics

Value: 81619 → 81620 → 81621

Parity: even

Prime: No

Previous Prime: 81619

Next Prime: 81629

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 2 ² × 5 × 7 × 11 × 53

Divisors: 1, 2, 4, 5, 7, 10, 11, 14, 20, 22

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2730 Try Today's Challenge

Representations

Binary: 10011111011010100

Octal: 237324

Duodecimal: 3B298

Hexadecimal: 13ed4

Square: 6661824400

Square Root: 285.69214199904064

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+2)X(k+2) 0..1 arrays with every 3X3 subblock sum of the two sums of the diagonal and antidiagonal minus the two minimums of the central column and central row nondecreasing horizontally, vertically and ne-to-sw antidiagonally. A254907

Number of bond-rooted polyenoids with n edges. A913

G.f. = b(2)*b(4)*b(6)/(x⁸-x³-x+1), where b(k) = (1-x^k)/(1-x). A266338

Numbers k such that A360331(k) = A360331(k+1). A360359

Number of (n+2)X(2+2) 0..1 arrays with every 3X3 subblock sum of the two sums of the diagonal and antidiagonal minus the two minimums of the central column and central row nondecreasing horizontally, vertically and ne-to-sw antidiagonally. A254901

Number of (5+2)X(n+2) 0..1 arrays with every 3X3 subblock sum of the two sums of the diagonal and antidiagonal minus the two minimums of the central column and central row nondecreasing horizontally, vertically and ne-to-sw antidiagonally. A254911

Number of ways to place 8 nonattacking queens on an 8 X n board. A172449

Table read by antidiagonals: Place k equally spaced points on each side of a regular n-gon and join every pair of these n·k points by a chord; T(n,k) (n >= 3, k >= 0) gives the number of edges in the resulting planar graph. A367305

Least m with n*(n+1)/2 divisors. A81620