Properties of the Number 21807

Twenty-One Thousand Eight Hundred Seven

Basics

Value: 21806 → 21807 → 21808

Parity: odd

Prime: No

Previous Prime: 21803

Next Prime: 21817

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 2423

Divisors: 1, 3, 9, 2423, 7269, 21807

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101010100101111

Octal: 52457

Duodecimal: 10753

Hexadecimal: 552f

Square: 475545249

Square Root: 147.6719336908676

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 3's in all partitions of n. A24787

Weighted count of equivalence classes of words w of length n+3 over {a, b, c, d, A, *} having exactly n letters, exactly three *'s, an even number of lowercase a's, and weight (-1)^A(w), where A(w) is the number of uppercase letters A. A390530

Numbers n such that the sum of the squares of the digits of nⁿ is a square. A171976

Numbers k such that 44·10^k + 3 is prime. A291606

Decimal expansion of 1/803. A21807