Properties of the Number 21516

Twenty-One Thousand Five Hundred Sixteen

Basics

Value: 21515 → 21516 → 21517

Parity: even

Prime: No

Previous Prime: 21503

Next Prime: 21517

Digit Sum: 15

Digital Root: 6

Palindrome: No

Factorization: 2 ² × 3 × 11 × 163

Divisors: 1, 2, 3, 4, 6, 11, 12, 22, 33, 44

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

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Representations

Binary: 101010000001100

Octal: 52014

Duodecimal: 10550

Hexadecimal: 540c

Square: 462938256

Square Root: 146.68333238647122

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

Record (maximal) gaps between prime triples (p, p+4, p+6). A201596

Even dodecagonal numbers: a(n) = 4·n*(5·n - 2). A193872

Number of permutations of [n] where each pair of adjacent elements differs by a prime. A367704

Magnetic Tower of Hanoi, total number of moves, optimally solving the [RED ; NEUTRAL ; BLUE] pre-colored puzzle. A183114

Trisection of A107926: The least number k such that there are primes p and q with p - q = 6·n+4, p + q = k, and p the least such prime >= k/2. A234956

Number of partitions of n, where the difference between the number of odd parts and the number of even parts is 9. A240018

Number of 3 X n 0..1 arrays with diagonals and antidiagonals unimodal and rows nondecreasing. A223950

Numbers k such that k - 13, k + 1, k + 5, k + 7, and k + 13 are all prime. A281937

Decimal expansion of 1/512. A21516

Numbers k such that k=(a+b)*c=a·b+c for more than one triple (a,b,c) with 1<c<a<=b. A329169