640348904 has 16 divisors (see below), whose sum is σ = 1293012420. Its totient is φ = 295545600.

The previous prime is 640348897. The next prime is 640348921. The reversal of 640348904 is 409843046.

640348904 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 585736804 + 54612100 = 24202^2 + 7390^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3078497 + ... + 3078704.

Almost surely, 2^640348904 is an apocalyptic number.

It is an amenable number.

640348904 is an abundant number, since it is smaller than the sum of its proper divisors (652663516).

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

640348904 is a wasteful number, since it uses less digits than its factorization.

640348904 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6157220 (or 6157216 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 38.

The square root of 640348904 is about 25305.1161625471. The cubic root of 640348904 is about 861.9304498304.

The spelling of 640348904 in words is "six hundred forty million, three hundred forty-eight thousand, nine hundred four".