Properties of the Number 21054

Twenty-One Thousand Fifty-Four

Basics

Value: 21053 → 21054 → 21055

Parity: even

Prime: No

Previous Prime: 21031

Next Prime: 21059

Digit Sum: 12

Digital Root: 3

Palindrome: No

Factorization: 2 × 3 × 11 ² × 29

Divisors: 1, 2, 3, 6, 11, 22, 29, 33, 58, 66

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 101001000111110

Octal: 51076

Duodecimal: 10226

Hexadecimal: 523e

Square: 443270916

Square Root: 145.09996554100212

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,k) is the n-th Rhonda number to base A002808(k), the k-th composite number; square array A(n,k), n>=1, k>=1, read by antidiagonals. A291925

Integers that are Rhonda numbers to base 9. A100973

G.f.: 1/(1 + x·d/dx log(η(x))), where η(x) is Dedekind's η(q) function without the q^1/24 factor. A180305

Index sequence to A089840: positions of bijections that preserve A127302 (the non-oriented form of binary trees) and whose behavior does not depend on whether there are internal or terminal nodes (leaves) in the neighborhood of any vertex. A153830

Generalized Catalan numbers for triangle A119335. A119365

Triangle read by rows, related to A108283. A108284

Sequence generated from Lim:_{n..inf.} Mⁿ, M = an infinite lower triangular matrix with (1,3,3,3,...) in every column, shifted down twice. A171370

a(n) = 25·n² + n. A173089

a(n) = Taylor coefficient at x=li(e) of the inverse of the function li(x) (the logarithm integral) multiplied by exp(n). A89963

a(n) = 841·n² + 29. A158665