639225968 has 20 divisors (see below), whose sum is σ = 1303685160. Its totient is φ = 302791104.

The previous prime is 639225941. The next prime is 639225989. The reversal of 639225968 is 869522936.

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, 1051055 + ... + 1051662.

It is an arithmetic number, because the mean of its divisors is an integer number (65184258).

Almost surely, 2^639225968 is an apocalyptic number.

It is an amenable number.

639225968 is an abundant number, since it is smaller than the sum of its proper divisors (664459192).

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

639225968 is a wasteful number, since it uses less digits than its factorization.

639225968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2102744 (or 2102738 counting only the distinct ones).

The product of its digits is 1399680, while the sum is 50.

The square root of 639225968 is about 25282.9185024198. The cubic root of 639225968 is about 861.4263189037.

The spelling of 639225968 in words is "six hundred thirty-nine million, two hundred twenty-five thousand, nine hundred sixty-eight".