Properties of the Number 21165

Twenty-One Thousand One Hundred Sixty-Five

Basics

Value: 21164 → 21165 → 21166

Parity: odd

Prime: No

Previous Prime: 21163

Next Prime: 21169

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 3 × 5 × 17 × 83

Divisors: 1, 3, 5, 15, 17, 51, 83, 85, 249, 255

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101001010101101

Octal: 51255

Duodecimal: 102B9

Hexadecimal: 52ad

Square: 447957225

Square Root: 145.4819576442385

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

Rhonda numbers in vigesimal number system. A255732

Conjecturally, largest attractor in '3x+(2n+1)' problem. A39515

List of codewords in binary lexicode with Hamming distance 7 written as decimal numbers. A75937

Odd composite numbers k such that cototient(k) - φ(k) = k - 2*φ(k) is an odd prime. A83255

Number of Motzkin n-paths with an even number of up steps. A107587

Odd n such that 2*φ(n) < n, but there does not exist an even k < n with φ(k) = φ(n). A118700

Large-number statistic from the enumeration of domino tilings of a 9-pillow of order n. A112843

Concatenation of n-th prime and n-th nonprime. A253910

Denominator of (1/3)*n*(n + 2)/((1 + 2·n)*(3 + 2·n)). A300295

Number of cyclic patterns of length n that avoid the vincular pattern 23-1-4. A346660