Properties of the Number -491

Four Hundred Ninety-One

Basics

Value: -492 → -491 → -490

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 14

Digital Root: 5

Palindrome: No

Factorization: 491

Divisors: 1, 491

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

5184 Try Today's Challenge

Representations

Binary: -111101011

Octal: -753

Duodecimal: -34B

Hexadecimal: -1eb

Square: 241081

Square Root: 22.15851980616034

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

Square array T(n,k), n >= 1, k >= 0, read by antidiagonals downwards, where T(n,k) = ∑_j=1..n (-k)^floor(n/j - 1). A345033

Expansion of e.g.f.: sin(r·x) / sqrt(1 + cos(r·x)²) where r = sqrt(2), odd powers only. A263246

Expansion of exp( ∑_n>=1 -σ(6·n)*xⁿ/n ) in powers of x. A283164

a(n) = ∑_k=1..n (-2)^floor(n/k - 1). A345034

Primes or negative values of primes of the form 8·n² - 298·n + 2113 for n >= 0. A217439

Primes or negative values of primes of the form 8·n² - 326·n + 2659 for n >= 0. A217440

a(n+1) = a(n) - a(floor(n/2)), with a(0)=0, a(1)=1. A62187

First differences of number of active (ON, black) cells in n-th stage of growth of two-dimensional cellular automaton defined by "Rule 485", based on the 5-celled von Neumann neighborhood. A272505

Expansion of ∑_k>=0 x^k*(k+1/2) / ∏_j=1..k (1 + j·x^j). A306704

a(n) = -n² + 21·n - 1. A332884