640630402 has 8 divisors (see below), whose sum is σ = 961066512. Its totient is φ = 320274900.

The previous prime is 640630399. The next prime is 640630411. The reversal of 640630402 is 204036046.

640630402 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 an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7077 + ... + 36487.

It is an arithmetic number, because the mean of its divisors is an integer number (120133314).

Almost surely, 2^640630402 is an apocalyptic number.

640630402 is a deficient number, since it is larger than the sum of its proper divisors (320436110).

640630402 is a wasteful number, since it uses less digits than its factorization.

640630402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40304.

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 640630402 is about 25310.6776282264. The cubic root of 640630402 is about 862.0567331483.

Adding to 640630402 its reverse (204036046), we get a palindrome (844666448).

The spelling of 640630402 in words is "six hundred forty million, six hundred thirty thousand, four hundred two".