Properties of the Number 21159

Twenty-One Thousand One Hundred Fifty-Nine

Basics

Value: 21158 → 21159 → 21160

Parity: odd

Prime: No

Previous Prime: 21157

Next Prime: 21163

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 3 ² × 2351

Divisors: 1, 3, 9, 2351, 7053, 21159

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

603 Try Today's Challenge

Representations

Binary: 101001010100111

Octal: 51247

Duodecimal: 102B3

Hexadecimal: 52a7

Square: 447703281

Square Root: 145.4613350688079

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

Starting numbers for which the RATS sequence has eventual period 3. A114613

Numbers of the form HMMSS with primes H < 24 and MM, SS < 60, for which the number of seconds after midnight, 3600·H+60·MM+SS, is also prime. A295011

a(n) = 40·n² - 1. A158598

Number of 1X5 integer matrices with each row summing to zero, row elements in nondecreasing order, rows in lexicographically nondecreasing order, and the sum of squares of the elements <= 2·n² (number of collections of 1 zero-sum 5-vectors with total modulus squared not more than 2·n², ignoring vector and component permutations). A192692

Sociable totient numbers of order 3: numbers k such that s(s(s(k))) = k, but s(k) ≠ k, where s(k) = A092693(k) is the sum of iterated φ function. A343243

Number of nX5 0..1 arrays avoiding 0 0 0 and 0 1 0 horizontally and 0 0 1 and 0 1 0 vertically. A207423

Decimal expansion of 1/155. A21159