Properties of the Number 20861

Twenty Thousand Eight Hundred Sixty-One

Basics

Value: 20860 → 20861 → 20862

Parity: odd

Prime: No

Previous Prime: 20857

Next Prime: 20873

Digit Sum: 17

Digital Root: 8

Palindrome: No

Factorization: 23 × 907

Divisors: 1, 23, 907, 20861

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: 101000101111101

Octal: 50575

Duodecimal: 100A5

Hexadecimal: 517d

Square: 435181321

Square Root: 144.43337564427412

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

Total number of nonprime parts in all partitions of n. A144119

Number of solutions to p(n) = ∑_i=1..n-1 c(i)*p(i) with c(i) in {-1,0,1} and p(n) = n-th prime. A215221

Number of solutions to n = ∑_i=1..π(n-1) c(i)*p(i) with c(i) in {-1,0,1}, p(n) = n-th prime and π = A000720. A215222

a(n) = 1 + n + ((n-1)*n²)/2. A218152

a(n) = 2 + n²*floor((n+3)/2) + floor(3·n/2). A370754

Decimal expansion of log₂(9). A20861

Number of ways to place 6 nonattacking grasshoppers on an n·n chessboard. A190579