640634204 has 12 divisors (see below), whose sum is σ = 1281268464. Its totient is φ = 274557504.

The previous prime is 640634201. The next prime is 640634209. The reversal of 640634204 is 402436046.

It is a happy number.

640634204 is an admirable number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640634201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11439869 + ... + 11439924.

It is an arithmetic number, because the mean of its divisors is an integer number (106772372).

Almost surely, 2^640634204 is an apocalyptic number.

It is an amenable number.

640634204 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.

640634204 is a wasteful number, since it uses less digits than its factorization.

640634204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22879804 (or 22879802 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 29.

The square root of 640634204 is about 25310.7527347568. The cubic root of 640634204 is about 862.0584385171.

The spelling of 640634204 in words is "six hundred forty million, six hundred thirty-four thousand, two hundred four".