Properties of the Number 21588

Twenty-One Thousand Five Hundred Eighty-Eight

Basics

Value: 21587 → 21588 → 21589

Parity: even

Prime: No

Previous Prime: 21587

Next Prime: 21589

Digit Sum: 24

Digital Root: 6

Palindrome: No

Factorization: 2 ² × 3 × 7 × 257

Divisors: 1, 2, 3, 4, 6, 7, 12, 14, 21, 28

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010001010100

Octal: 52124

Duodecimal: 105B0

Hexadecimal: 5454

Square: 466041744

Square Root: 146.92855406625358

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 nXk 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 1 1 and 1 0 1 vertically. A208688

T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 0 1 horizontally and 0 1 1 and 1 1 0 vertically. A208840

Numbers that are the sum of eight fourth powers in nine or more ways. A345584

Numbers that are the sum of eight fourth powers in ten or more ways. A345585

Numbers that are the sum of eight fourth powers in exactly ten ways. A345842

Consider the Diophantine equation x³ + y³ = z³ - 1 (x < y < z) or 'Fermat near misses'. The values of z (see A050787) are arranged in monotonically increasing order. Sequence gives values of y. A50789

Number of partitions of n having no even singletons. A265254

Decimal representation of the x-axis, from the left edge to the origin, of the n-th stage of growth of the two-dimensional cellular automaton defined by "Rule 145", based on the 5-celled von Neumann neighborhood. A279150

Number of (w,x,y,z) with all terms in {1,...,n} and w<|x-y|+|y-z|. A212568

a(n) is the number of distinct (modulo geometric D3-operations) nonsymmetric (no reflective nor rotational symmetry) patterns which can be formed by an equilateral triangular arrangement of closely packed black and white cells satisfying the local matching rule of Pascal's triangle modulo 2, where n is the number of cells in each edge of the arrangement. The matching rule is such that any elementary top-down triangle of three neighboring cells in the arrangement contains either one or three white cells. A60552