Properties of the Number -80

Eighty

Basics

Value: -81 → -80 → -79

Parity: even

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 8

Digital Root: 8

Palindrome: No

Factorization: 2 ⁴ × 5

Divisors: 1, 2, 4, 5, 8, 10, 16, 20, 40, 80

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -1010000

Octal: -120

Duodecimal: -68

Hexadecimal: -50

Square: 6400

Square Root: 8.94427190999916

Classification

Fibonacci: No

Bell Number: No

Factorial Number: No

Regular Number: Yes

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

Triangle T, read by rows, such that the m-th matrix power satisfies T^m = I + m*(T - I) and consequently the matrix logarithm satisfies log(T) = T - I, where I is the identity matrix. A112555

a(n) is the sum of the elements on the antidiagonal of the difference table of the divisors of n. A161700

Riordan array (1/(1-x), x/(1+x)). A112468

Triangle read by rows: terms of a binomial decomposition of 1 as Sum(k=0..n)T(n,k). A244117

Expansion of - (1/8) theta₃''(0, q) / theta₃(0, q) in powers of q. A186690

Determinant of the symmetric n X n matrix A defined by A[i,j] = |i-j| for 1 <= i,j <= n. A85750

Triangle read by rows of coefficients of Chebyshev's U(n,x) polynomials (exponents in increasing order). A53117

Coefficients in 1/(1+P(x)), where P(x) is the generating function of the primes. A30018

Real part of the sum of divisors function σ(n) generalized for Gaussian integers. A103228

Irregular triangle read by rows: coefficients of U(n,x), Chebyshev polynomials of the second kind with exponents in decreasing order. A133156