Properties of the Number -7581

Five Hundred Eighty-One

Basics

Value: -7582 → -7581 → -7580

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 21

Digital Root: 3

Palindrome: No

Factorization: 3 × 7 × 19 ²

Divisors: 1, 3, 7, 19, 21, 57, 133, 361, 399, 1083

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -1110110011101

Octal: -16635

Duodecimal: -4479

Hexadecimal: -1d9d

Square: 57471561

Square Root: 87.06893820416096

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

Number triangle read by rows, related to exp(x)/(cos(x) + sin(x)). A117442

a(n) = (17 - 2·n)*n². A15234

Dedekind numbers or Dedekind's problem: number of monotone Boolean functions of n variables, number of antichains of subsets of an n-set, number of elements in a free distributive lattice on n generators, number of Sperner families. A372

Heinz numbers of integer partitions whose reciprocal sum is 1. A316855

a(n) = a(n-3) + a(n-4), with a(0)=1, a(1)=a(2)=0, a(3)=1. A17817

Number of reduced words of length n in the Weyl group B₇. A161716

a(n) = ∑_k=0..n C(n-k,3k). A3522

Rectangular table, read by antidiagonals, such that the g.f. of row n, R_n(y), satisfies: R_n(y) = ∑_k>=0 y^k * [R_n·k(y)]^n·k for n>=0, with R₀(y)=1/(1-y). A124560

T(n,k)=Number of -k..k arrays of n elements with first and second differences also in -k..k. A201088

a(n) = (n-1)²*(n+1). A152618