Properties of the Number 21155

Twenty-One Thousand One Hundred Fifty-Five

Basics

Value: 21154 → 21155 → 21156

Parity: odd

Prime: No

Previous Prime: 21149

Next Prime: 21157

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 5 × 4231

Divisors: 1, 5, 4231, 21155

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 101001010100011

Octal: 51243

Duodecimal: 102AB

Hexadecimal: 52a3

Square: 447534025

Square Root: 145.4475850607359

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

The q expansion of λ⁵, a Hauptmodul for Gamma₁(5). A78905

Structured meta-anti-prism numbers, the n-th number from a structured n-gonal anti-prism number sequence. A100185

The expansion of R(q)^-5 in powers of q where R() is the Rogers-Ramanujan continued fraction. A229793

a(n) = ∑_i=0..n digsum₅(i)⁴, where digsum₅(i) = A053824(i). A231671

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

Indices of primes in sequence defined by A(0) = 33, A(n) = 10·A(n-1) - 7 for n > 0. A56252

a(n) = A120020(n)/n = coefficient of xⁿ in the n-th self-composition of the g.f. of A120010, divided by n, for n>=1. A120022

Number of partitions p of n such that (number of even numbers in p) is a part of p. A241544

Triangular array read by rows: T(n,k) is the number of transitive relations on {1,2,...,n} that have exactly k reflexive points, n>=0, 0<=k<=n. A245767

Number of (w,x,y) with all terms in {0,...,n} and x ≠ min(|w-x|, |x-y|). A213502