Properties of the Number -1081

Eighty-One

Basics

Value: -1082 → -1081 → -1080

Parity: odd

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 10

Digital Root: 1

Palindrome: No

Factorization: 23 × 47

Divisors: 1, 23, 47, 1081

Polygonal

Triangular: Yes

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

Today's Target

5184 Try Today's Challenge

Representations

Binary: -10000111001

Octal: -2071

Duodecimal: -761

Hexadecimal: -439

Square: 1168561

Square Root: 32.87856444554719

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 (1+x)/(1-x²+x³). A124745

G.f. satisfies x = A(x)*(1-A(x))/(1-A(x)-(A(x))²). A108623

Expansion of ∑_k>0 x^2·k/(1+x^k)³. A363022

G.f. satisfies x = A(x)*(1+A(x))/(1-A(x)-(A(x))²). A108624

a(n) = -n² + 21·n - 1. A332884

Expansion of e.g.f.: cosh(x)/exp(sin(x)). A9184

Triangular numbers: a(n) = binomial(n+1,2) = n*(n+1)/2 = 0 + 1 + 2 + ... + n. A217

Padovan sequence (or Padovan numbers): a(n) = a(n-2) + a(n-3) with a(0) = 1, a(1) = a(2) = 0. A931

Second hexagonal numbers: a(n) = n*(2·n + 1). A14105

a(0) = 0, a(1) = a(2) = a(3) = 1; thereafter, a(n) = a(n-1) + a(n-2) + a(n-4). A5251