Properties of the Number 21679

Twenty-One Thousand Six Hundred Seventy-Nine

Basics

Value: 21678 → 21679 → 21680

Parity: odd

Prime: No

Previous Prime: 21673

Next Prime: 21683

Digit Sum: 25

Digital Root: 7

Palindrome: No

Factorization: 7 × 19 × 163

Divisors: 1, 7, 19, 133, 163, 1141, 3097, 21679

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 101010010101111

Octal: 52257

Duodecimal: 10667

Hexadecimal: 54af

Square: 469979041

Square Root: 147.23790272888297

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 sensed planar maps with n vertices and 2 faces. A380237

Neither square nor square + prime. A20495

a(n) = C(n+2, 2) + C(n+2, 3) + C(n+2, 4) + C(n+2, 5). A27660

Cogrowth sequence of the 12-element dicyclic group Dic12 = <S,T | S⁶, T⁴, STST³, S^3T^2>. A377656

a(n) = n*(3·n² + 3·n + 1). A249354

Strong pseudoprimes to base 58. A20284

a(n) = n * (binomial(n + 1, 3) + 1). A329523

Cycle class sequence c(n) (the number of true cycles of length n in which a certain node is included) for zeolite NES = ν-87 H4[Al4Si64O136].nH2O starting with a T1 atom. A19202

Odd numbers which are not squares and cannot be written as a sum of a prime and a square. A308516

Numbers that are not the sum of a square and a prime. A14090