640671204 has 12 divisors (see below), whose sum is σ = 1494899504. Its totient is φ = 213557064.

The previous prime is 640671193. The next prime is 640671209. The reversal of 640671204 is 402176046.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (640671209) 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, 26694622 + ... + 26694645.

Almost surely, 2^640671204 is an apocalyptic number.

It is an amenable number.

640671204 is an abundant number, since it is smaller than the sum of its proper divisors (854228300).

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

640671204 is a wasteful number, since it uses less digits than its factorization.

640671204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53389274 (or 53389272 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 30.

The square root of 640671204 is about 25311.4836388545. The cubic root of 640671204 is about 862.0750343362.

The spelling of 640671204 in words is "six hundred forty million, six hundred seventy-one thousand, two hundred four".