Properties of the Number 21239

Twenty-One Thousand Two Hundred Thirty-Nine

Basics

Value: 21238 → 21239 → 21240

Parity: odd

Prime: No

Previous Prime: 21227

Next Prime: 21247

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 67 × 317

Divisors: 1, 67, 317, 21239

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001011110111

Octal: 51367

Duodecimal: 1035B

Hexadecimal: 52f7

Square: 451095121

Square Root: 145.7360627984714

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

T(n,k)=Number of length (n+k)X1 arrays of occupancy after each element moves up to +-k places but not 0. A222555

Minimal element in the primitive 3x-k cycle with the conjectured record-breaking maximal element A226683(n). A226685

Least number k >= 0 such that (n!-k)/n is prime. A245696

Retrograde trajectory of 13 under map n -> A132948(n). A132947

Number of intervals in the lattice of Motzkin paths of length n. A379034

Number of (n+4)X1 arrays of occupancy after each element moves up to +-4 places but not 0. A222551

Numbers k such that 8k+1, 12k+1 and 24k+1 are primes and the last two are also of the form x² + 27y², so the tetrahedral number T(24k+1) is a Fermat pseudoprime to base 2. A321867

Number of compositions of n having exactly one part whose multiplicity equals its size. A393566

Decimal expansion of 1/235. A21239