Properties of the Number 21555

Twenty-One Thousand Five Hundred Fifty-Five

Basics

Value: 21554 → 21555 → 21556

Parity: odd

Prime: No

Previous Prime: 21529

Next Prime: 21557

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 5 × 479

Divisors: 1, 3, 5, 9, 15, 45, 479, 1437, 2395, 4311

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 101010000110011

Octal: 52063

Duodecimal: 10583

Hexadecimal: 5433

Square: 464618025

Square Root: 146.81621163890588

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

a(n) = ∑_i=0..n digsum₈(i)³, where digsum₈(i) = A053829(i). A231682

Every prefix prime in base 6 (written in base 6). A24766

Array read by antidiagonals: T(m,n) = number of maximal irredundant sets in the grid graph P_m X P_n. A291439

Number of ways to write a + b + c = d + e = f with {a,b,c,d,e,f} a subset of [n] of size 6 and a < b < c and d < e. A362717

Numbers k such that the decimal part of k^1/6 starts with a 'nine digits' anagram. A34281

Number of nondecreasing strings of numbers x(i=1..8) in -n..n with sum x(i)³ equal to 0. A188282

Number of maximal irredundant sets in the n X n grid graph. A290790

Number of unlabeled biconnected graphs on n vertices without 4-cycles or 5-cycles. A366223

Trajectory of 1 under map n->11n+1 if n odd, n->n/2 if n even. A33963

Trajectory of 3 under map n->11n+1 if n odd, n->n/2 if n even. A37103