Properties of the Number 21538

Twenty-One Thousand Five Hundred Thirty-Eight

Basics

Value: 21537 → 21538 → 21539

Parity: even

Prime: No

Previous Prime: 21529

Next Prime: 21557

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 2 × 11 ² × 89

Divisors: 1, 2, 11, 22, 89, 121, 178, 242, 979, 1958

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101010000100010

Octal: 52042

Duodecimal: 1056A

Hexadecimal: 5422

Square: 463885444

Square Root: 146.75830470538966

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

Number of rucksack partitions of n: every consecutive constant subsequence has a different sum. A353864

Number of partitions of n such that (greatest part) is not = (multiplicity of greatest part). A240057

Triangle read by rows: T(n,k) is the number of Schroeder paths of length 2n and having k peaks at even height. A101895

Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 182", based on the 5-celled von Neumann neighborhood. A270632

Numbers k such that usigma(uphi(k)) = uphi(usigma(k)), where usigma is the sum of unitary divisors function (A034448) and uphi is the unitary totient function (A047994). A329730

Expansion of 1/q(x) where q(x) = x¹⁶*p(1/x) and p(x) = -332914995·x - 121099959·x² - 54262863·x³ - 37433763·x⁴ - 1488468·x⁵ - 4442464·x⁶ + 462362·x⁷ - 241686·x⁸ + 63542·x⁹ + 26·x¹⁰ + 3732·x¹¹ + 776·x¹² + 113·x¹³ + 45·x¹⁴ + x¹⁵ + x¹⁶. A158376

Expansion of g.f. A(x) satisfying A(x) = 1 + x*(A(x)² + A(-x)²)/2 + x*(A(x)⁴ - A(-x)⁴)/2. A368629

Number of nX4 0..1 arrays with each 1 horizontally, vertically or antidiagonally adjacent to 1 or 2 neighboring 1s. A296382

Decimal expansion of 1/534. A21538