640301644 has 6 divisors (see below), whose sum is σ = 1120527884. Its totient is φ = 320150820.

The previous prime is 640301603. The next prime is 640301671. The reversal of 640301644 is 446103046.

It is a happy number.

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 as a sum of consecutive naturals, namely, 80037702 + ... + 80037709.

Almost surely, 2^640301644 is an apocalyptic number.

It is an amenable number.

640301644 is a deficient number, since it is larger than the sum of its proper divisors (480226240).

640301644 is a wasteful number, since it uses less digits than its factorization.

640301644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160075415 (or 160075413 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 640301644 is about 25304.1823420556. The cubic root of 640301644 is about 861.9092448097.

The spelling of 640301644 in words is "six hundred forty million, three hundred one thousand, six hundred forty-four".