Properties of the Number 21517

Twenty-One Thousand Five Hundred Seventeen

Basics

Value: 21516 → 21517 → 21518

Parity: odd

Prime: Yes

Previous Prime: 21503

Next Prime: 21521

Digit Sum: 16

Digital Root: 7

Palindrome: No

Factorization: 21517

Divisors: 1, 21517

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2730 Try Today's Challenge

Representations

Binary: 101010000001101

Octal: 52015

Duodecimal: 10551

Hexadecimal: 540d

Square: 462981289

Square Root: 146.68674105044394

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

Initial term in sequence of four consecutive primes separated by 3 consecutive differences each <=6 (i.e., when d=2,4 or 6) and forming d-pattern=[4,2,6]; short d-string notation of pattern = [426]. A78850

T(n,k)=Number of nXk 0..1 arrays avoiding 0 0 0 and 0 1 1 horizontally and 0 1 0 and 1 0 1 vertically. A207467

Generalized Catalan numbers C(6; n). A64089

Primes in which the digit string can be partitioned into three parts such that the sum of the first two is equal to the third, and the second part is nonzero. A88291

Number of partitions p of n such that the multiplicity of (min(p) + max(p))/2 is a part. A240497

Sixth diagonal of triangle A064094. A64302

Primes p such that p+12, p+1234 and p+123456 are also prime. A236304

Number of permutations of length n that avoid the patterns 4123, 4231, and 4312. A257562

Denominators of continued fraction convergents to sqrt(931). A42801

Group the natural numbers so that the n-th group contains n numbers whose sum as well as the group product +1 is prime. Sequence contains the primes arising as the sum of the terms of groups. A92946