Properties of the Number 21616

Twenty-One Thousand Six Hundred Sixteen

Basics

Value: 21615 → 21616 → 21617

Parity: even

Prime: No

Previous Prime: 21613

Next Prime: 21617

Digit Sum: 16

Digital Root: 7

Palindrome: No

Factorization: 2 ⁴ × 7 × 193

Divisors: 1, 2, 4, 7, 8, 14, 16, 28, 56, 112

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101010001110000

Octal: 52160

Duodecimal: 10614

Hexadecimal: 5470

Square: 467251456

Square Root: 147.02380759591284

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 different multisets that can be obtained by choosing a prime index (or a prime factor) of each integer from 2 to n. A355746

Irregular triangle read by rows: T(n,k) is the number of degree-n permutations without overlaps which furnish k new permutations without overlaps upon the addition of an (n+1)st element, 2 <= k <= 1 + floor(n/2). A259689

a(n)*a(n+3) - a(n+1)*a(n+2) = 2ⁿ, given a(0)=1, a(1)=1, a(2)=6. A80879

a(n)*a(n+3) - a(n+1)*a(n+2) = 2ⁿ, given a(0)=1, a(1)=3, a(2)=7. A80882

Largest achievable determinant of a 3 X 3 matrix whose elements are 9 distinct nonnegative integers chosen from the range 0..n. A97401

Expansion of g.f. 1/((1-4·x)*(1-6·x)*(1-8·x)). A19333

Numbers k whose binary expansion contains 2 adjacent 1's and A391571(k) = k. A391581

a(n) = the number of permutations (p(1), p(2), ..., p(n)) of (1,2,...,n) where, for each k (2 <= k <= n), the sign of (p(k) - p(k-1)) equals the sign of (p(n+2-k) - p(n+1-k)). A137782

a(n) = 49·n² + 7. A158481

Number of partitions of n with ten parts in which no part occurs more than twice. A320598