640523708 has 24 divisors (see below), whose sum is σ = 1248839424. Its totient is φ = 284951600.

The previous prime is 640523641. The next prime is 640523713. The reversal of 640523708 is 807325046.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 152798 + ... + 156933.

It is an arithmetic number, because the mean of its divisors is an integer number (52034976).

Almost surely, 2^640523708 is an apocalyptic number.

It is an amenable number.

640523708 is a deficient number, since it is larger than the sum of its proper divisors (608315716).

640523708 is a wasteful number, since it uses less digits than its factorization.

640523708 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 309793 (or 309791 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 35.

The square root of 640523708 is about 25308.5698529174. The cubic root of 640523708 is about 862.0088733177.

The spelling of 640523708 in words is "six hundred forty million, five hundred twenty-three thousand, seven hundred eight".