Properties of the Number 21268

Twenty-One Thousand Two Hundred Sixty-Eight

Basics

Value: 21267 → 21268 → 21269

Parity: even

Prime: No

Previous Prime: 21247

Next Prime: 21269

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 2 ² × 13 × 409

Divisors: 1, 2, 4, 13, 26, 52, 409, 818, 1636, 5317

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101001100010100

Octal: 51424

Duodecimal: 10384

Hexadecimal: 5314

Square: 452327824

Square Root: 145.83552379307312

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

Numbers k that divide 4^k + 4. A15889

Numbers that are the sum of eight fourth powers in nine or more ways. A345584

Numbers that are the sum of eight fourth powers in ten or more ways. A345585

Expansion of ∏_k>=1 ((1 + k·x^k) / (1 + x^k)). A268500

Pseudo-Kaprekar triples: q such that if q=x+y+z, then q³=x·10ⁱ + y·10^j + z, where (y·10^j+z < 10ⁱ) and z < 10^j. A60768

A hexagonal spiral Fibonacci sequence. A94926

Trails of length n on square lattice. A6817

Number of n X 3 0..4 arrays with each element·equal to the number its horizontal and vertical neighbors equal to 2,0,3,4,1 for x=0,1,2,3,4. A196205

Sum of the asymmetry degrees of all compositions of n with parts in {2,1,3,5,7,9,...}. A275447

Numbers n, not divisible by 3, 5, 7 or 11, such that A000203(n)-n-1 and 2·n+1-A000203(n) are prime numbers. A180268