640344404 has 12 divisors (see below), whose sum is σ = 1280688864. Its totient is φ = 274433304.

The previous prime is 640344361. The next prime is 640344451. The reversal of 640344404 is 404443046.

640344404 is an admirable number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11434694 + ... + 11434749.

It is an arithmetic number, because the mean of its divisors is an integer number (106724072).

Almost surely, 2^640344404 is an apocalyptic number.

It is an amenable number.

640344404 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

640344404 is a wasteful number, since it uses less digits than its factorization.

640344404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22869454 (or 22869452 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 29.

The square root of 640344404 is about 25305.0272475649. The cubic root of 640344404 is about 861.9284307769.

The spelling of 640344404 in words is "six hundred forty million, three hundred forty-four thousand, four hundred four".