640330066 has 16 divisors (see below), whose sum is σ = 988473024. Its totient is φ = 310874544.

The previous prime is 640330037. The next prime is 640330073. The reversal of 640330066 is 660033046.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28621 + ... + 45823.

It is an arithmetic number, because the mean of its divisors is an integer number (61779564).

Almost surely, 2^640330066 is an apocalyptic number.

640330066 is a deficient number, since it is larger than the sum of its proper divisors (348142958).

640330066 is a wasteful number, since it uses less digits than its factorization.

640330066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17745.

The product of its (nonzero) digits is 7776, while the sum is 28.

The square root of 640330066 is about 25304.7439425891. The cubic root of 640330066 is about 861.9219975606.

The spelling of 640330066 in words is "six hundred forty million, three hundred thirty thousand, sixty-six".