Properties of the Number -66

Sixty-Six

Basics

Value: -67 → -66 → -65

Parity: even

Prime: No

Previous Prime:

Next Prime: 1

Digit Sum: 12

Digital Root: 3

Palindrome: Yes

Factorization: 2 × 3 × 11

Divisors: 1, 2, 3, 6, 11, 22, 33, 66

Polygonal

Triangular: Yes

Square: No

Pentagonal: No

Hexagonal: Yes

Heptagonal: No

Tetrahedral: No

Today's Target

2196 Try Today's Challenge

Representations

Binary: -1000010

Octal: -102

Duodecimal: -56

Hexadecimal: -42

Square: 4356

Square Root: 8.12403840463596

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

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

Nonzero coefficients of the Swiss-Knife polynomials for the computation of Euler, tangent, and Bernoulli numbers (triangle read by rows). A153641

The bottom entry in the difference table of the divisors of n. A187202

Second differences of consecutive perfect powers (A001597). First differences of A053289. A376559

a(n) = μ(n)*φ(n) where μ(n) is the Mobius function (A008683) and φ(n) is the Euler totient function (A000010). A97945

Dirichlet inverse of the deficiency of n, A033879. A323910

a(n) = A326126(n) - n, where A326126 gives the sum of all other divisors of n except the squarefree part of n. A326127

Negate primes in factorizations of divisors of n, then sum. A61020

Expansion of (1 - η(q)⁵ / η(q⁵)) / 5 in powers of q. A109091