Properties of the Number 20917

Twenty Thousand Nine Hundred Seventeen

Basics

Value: 20916 → 20917 → 20918

Parity: odd

Prime: No

Previous Prime: 20903

Next Prime: 20921

Digit Sum: 19

Digital Root: 1

Palindrome: No

Factorization: 13 × 1609

Divisors: 1, 13, 1609, 20917

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

4823 Try Today's Challenge

Representations

Binary: 101000110110101

Octal: 50665

Duodecimal: 10131

Hexadecimal: 51b5

Square: 437520889

Square Root: 144.62710672622887

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

Semiprimes in A003215. A113530

Numbers that are the sum of eight fourth powers in exactly eight ways. A345840

Numbers k such that (2^k - k - 1)*2^k + 1 is prime. A201362

a(n) = 12·n² + 18·n + 7. A154105

Ulam's spiral (SSW spoke). A143838

Gaps of 6 in sequence A038593 (lower terms). A38651

E.g.f. A(x) satisfies A(x) = exp( x*(A(x) + A(w·x) + A(w²*x))/3 ), where w = exp(2*π*i/3). A385691

Numbers k such that 93·2^k+1 is prime. A32396

Partial sums of the number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 374", based on the 5-celled von Neumann neighborhood. A271459

Numbers whose base-12 representation has exactly 5 runs. A43654