Properties of the Number 51680

Fifty-One Thousand Six Hundred Eighty

Basics

Value: 51679 → 51680 → 51681

Parity: even

Prime: No

Previous Prime: 51679

Next Prime: 51683

Digit Sum: 20

Digital Root: 2

Palindrome: No

Factorization: 2 ⁵ × 5 × 17 × 19

Divisors: 1, 2, 4, 5, 8, 10, 16, 17, 19, 20

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: 1100100111100000

Octal: 144740

Duodecimal: 25AA8

Hexadecimal: c9e0

Square: 2670822400

Square Root: 227.33235581412515

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

T(n,k)=Number of (n+1)X(k+1) 0..3 arrays with the sums of 2X2 subblocks nondecreasing rightwards and downwards. A204309

a(1) = 1, a(2) = 0; for n > 2, a(n) = n·Fibonacci(n-2) (with the convention Fibonacci(0)=0, Fibonacci(1)=1). A6490

Expansion of ∏_k>=1 (1 - x^k)²⁰. A10826

Fibonacci sequence beginning 0, 20. A22354

Number of cycles of length 4 in the queen graph associated with an n X n chessboard. A156001

a(n) = (Lucas(2·n) - Lucas(n))/2. A49681

Number of hands that peg n points in the "show" phase of 6-card cribbage. A66354

Numbers k such that φ(k) = bigomega(k)*τ(k)². A68540

Number of (n+1)X3 0..3 arrays with the sums of 2X2 subblocks nondecreasing rightwards and downwards. A204304

Number of (n+1)X(n+1) 0..3 arrays with the sums of 2X2 subblocks nondecreasing rightwards and downwards. A204302