664042666 has 16 divisors (see below), whose sum is σ = 1198272960. Its totient is φ = 269611200.

The previous prime is 664042607. The next prime is 664042693. The reversal of 664042666 is 666240466.

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, 1247935 + ... + 1248466.

It is an arithmetic number, because the mean of its divisors is an integer number (74892060).

Almost surely, 2^664042666 is an apocalyptic number.

664042666 is a deficient number, since it is larger than the sum of its proper divisors (534230294).

664042666 is a wasteful number, since it uses less digits than its factorization.

664042666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2496429.

The product of its (nonzero) digits is 248832, while the sum is 40.

The square root of 664042666 is about 25769.0253211098. The cubic root of 664042666 is about 872.4328198453.

The spelling of 664042666 in words is "six hundred sixty-four million, forty-two thousand, six hundred sixty-six".