Properties of the Number -42

Forty-Two

Basics

Value: -43 → -42 → -41

Parity: even

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 6

Digital Root: 6

Palindrome: No

Factorization: 2 × 3 × 7

Divisors: 1, 2, 3, 6, 7, 14, 21, 42

Polygonal

Triangular: No

Square: No

Pentagonal: No

Hexagonal: No

Heptagonal: No

Tetrahedral: No

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Representations

Binary: -101010

Octal: -52

Duodecimal: -36

Hexadecimal: -2a

Square: 1764

Square Root: 6.48074069840786

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

Dirichlet inverse of Euler totient function (A000010). A23900

Abundance of n, or (sum of divisors of n) - 2n. A33880

Triangle of Lah numbers. A8297

a(n) = n * μ(n), where μ is the Möbius function A008683. A55615

a(n) = 2 - n. A22958

A(n,k) is the n-th derivative of f_k at x=1, and f_k is the k-th of all functions that are representable as x^x^...^x with m>=1 x's and parentheses inserted in all possible ways; square array A(n,k), n>=0, k>=1, read by antidiagonals. A215703

Carlitz-Riordan q-Catalan numbers (recurrence version) for q = -1. A90192

The matrix inverse of the unsigned Lah numbers A271703. A111596

n-th derivative of x^x at x=1. Also called Lehmer-Comtet numbers. A5727

Triangle read by rows: T(n,k) = T(n-1,k-1) + T(n-1,k), 0 < k < n with T(n,0) = n and T(n,n) = -n. A214292