666685606586666 has 16 divisors (see below), whose sum is σ = 1002657469580424. Its totient is φ = 332466940882944.

The previous prime is 666685606586581. The next prime is 666685606586711.

666685606586666 is nontrivially palindromic in base 10.

666685606586666 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 457065275437225 + 209620331149441 = 21379085^2 + 14478271^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 119987345 + ... + 125420628.

Almost surely, 2^{666685606586666} is an apocalyptic number.

666685606586666 is a deficient number, since it is larger than the sum of its proper divisors (335971862993758).

666685606586666 is a wasteful number, since it uses less digits than its factorization.

666685606586666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245411545.

The product of its (nonzero) digits is 96745881600, while the sum is 86.

The spelling of 666685606586666 in words is "six hundred sixty-six trillion, six hundred eighty-five billion, six hundred six million, five hundred eighty-six thousand, six hundred sixty-six".