666406604666 has 64 divisors (see below), whose sum is σ = 1144070718336. Its totient is φ = 288441753600.

The previous prime is 666406604641. The next prime is 666406604681.

It is a happy number.

666406604666 is nontrivially palindromic in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9190445 + ... + 9262671.

It is an arithmetic number, because the mean of its divisors is an integer number (17876104974).

Almost surely, 2^666406604666 is an apocalyptic number.

666406604666 is a deficient number, since it is larger than the sum of its proper divisors (477664113670).

666406604666 is a wasteful number, since it uses less digits than its factorization.

666406604666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72527.

The product of its (nonzero) digits is 26873856, while the sum is 56.

The spelling of 666406604666 in words is "six hundred sixty-six billion, four hundred six million, six hundred four thousand, six hundred sixty-six".