Properties of the Number 21561

Twenty-One Thousand Five Hundred Sixty-One

Basics

Value: 21560 → 21561 → 21562

Parity: odd

Prime: No

Previous Prime: 21559

Next Prime: 21563

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 7187

Divisors: 1, 3, 7187, 21561

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101010000111001

Octal: 52071

Duodecimal: 10589

Hexadecimal: 5439

Square: 464876721

Square Root: 146.83664392786972

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

Expansion of (1 + 10·x + 20·x² + 10·x³ + x⁴)/(1-x)⁵. A160747

a(n) = ((3 + 2·sqrt(2))*(3 + sqrt(2))ⁿ + (3 - 2·sqrt(2))*(3 - sqrt(2))ⁿ)/2. A163606

Numbers n such that n+/-2 and n²+/-2 are all primes. A189051

Number of tilings of a 9 X n rectangle using integer-sided rectangular tiles of area 9. A220126

Number of symmetric types of (3,2n)-hypergraphs under action of complementing group C(3,2). A55780

Expansion of e.g.f. exp(cos(x)/exp(x) - 1). A305708

Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite MFS = ZSM-57 H1.5[Al1.5Si34.5O72] starting with a T1 atom. A19170

Decimal expansion of 1/557. A21561