Properties of the Number -2556

Five Hundred Fifty-Six

Basics

Value: -2557 → -2556 → -2555

Parity: even

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 18

Digital Root: 9

Palindrome: No

Factorization: 2 ² × 3 ² × 71

Divisors: 1, 2, 3, 4, 6, 9, 12, 18, 36, 71

Polygonal

Triangular: Yes

Square: No

Pentagonal: No

Hexagonal: Yes

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: -100111111100

Octal: -4774

Duodecimal: -1590

Hexadecimal: -9fc

Square: 6533136

Square Root: 50.556898639058154

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

Expansion of ∏_k>0 1/(1 + x^k)^k·3. A279031

a(n) = a(n-2) - (a(n-1) - a(n-2)) if (n mod 2) = 0, otherwise a(n) = a(n-1) - (a(n-3) - a(n-4)), with a(0) = 0, a(1) = 1, a(2) = -1, a(3) = 2. A135690

Expansion of (f(-x²) / φ(-x³))² in powers of·where φ(), f() are Ramanujan θ functions. A233034

Low-temperature susceptibility expansion for hexagonal lattice (Potts model, q=4). A57387

Triangle T(n,k) read by rows: the coefficient [x^k] of the polynomial ∏_i=1..n (i+1)*x-i in row n>=0 and column 0<=k<=n. A142070

First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 187", based on the 5-celled von Neumann neighborhood. A270676

A triangle of infinite sum coefficients with: Limit[Log[1-x],x->0]=-x: p(x,y)=1+n!*x^{n - 1}*Sum[x^k/(k·Binomial[n + k, k]), {k, 1, Infinity}]; such that Log[1-x]->-x. A157047

Hexagonal numbers: a(n) = n*(2·n-1). A384

Numbers obtained by reinterpreting base-2 representation of n in primorial base: a(0) = 0, a(2n) = A276154(a(n)), a(2n+1) = 1 + A276154(a(n)). A276156

Triangular numbers (A000217) with prime indices. A34953