640352664 has 48 divisors (see below), whose sum is σ = 1982045520. Its totient is φ = 182957760.

The previous prime is 640352653. The next prime is 640352707. The reversal of 640352664 is 466253046.

640352664 is a `hidden beast` number, since 640 + 3 + 5 + 2 + 6 + 6 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 634767 + ... + 635774.

It is an arithmetic number, because the mean of its divisors is an integer number (41292615).

Almost surely, 2^640352664 is an apocalyptic number.

It is an amenable number.

640352664 is an abundant number, since it is smaller than the sum of its proper divisors (1341692856).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

640352664 is a wasteful number, since it uses less digits than its factorization.

640352664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1270560 (or 1270553 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 36.

The square root of 640352664 is about 25305.1904557148. The cubic root of 640352664 is about 861.9321368545.

The spelling of 640352664 in words is "six hundred forty million, three hundred fifty-two thousand, six hundred sixty-four".