640432318 has 8 divisors (see below), whose sum is σ = 961389648. Its totient is φ = 319969104.

The previous prime is 640432307. The next prime is 640432409. The reversal of 640432318 is 813234046.

640432318 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 640432318.

It is a congruent number.

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, 120271 + ... + 125482.

It is an arithmetic number, because the mean of its divisors is an integer number (120173706).

Almost surely, 2^640432318 is an apocalyptic number.

640432318 is a deficient number, since it is larger than the sum of its proper divisors (320957330).

640432318 is a wasteful number, since it uses less digits than its factorization.

640432318 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247058.

The product of its (nonzero) digits is 13824, while the sum is 31.

The square root of 640432318 is about 25306.7642736087. The cubic root of 640432318 is about 861.9678741910.

The spelling of 640432318 in words is "six hundred forty million, four hundred thirty-two thousand, three hundred eighteen".