640702304 has 48 divisors (see below), whose sum is σ = 1388995776. Its totient is φ = 288489600.

The previous prime is 640702303. The next prime is 640702313. The reversal of 640702304 is 403207046.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640702303) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29159 + ... + 46169.

It is an arithmetic number, because the mean of its divisors is an integer number (28937412).

Almost surely, 2^640702304 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 640702304, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (694497888).

640702304 is an abundant number, since it is smaller than the sum of its proper divisors (748293472).

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

640702304 is a wasteful number, since it uses less digits than its factorization.

640702304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17139 (or 17131 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 26.

The square root of 640702304 is about 25312.0979770544. The cubic root of 640702304 is about 862.0889833008.

The spelling of 640702304 in words is "six hundred forty million, seven hundred two thousand, three hundred four".