639632748 has 12 divisors (see below), whose sum is σ = 1492476440. Its totient is φ = 213210912.

The previous prime is 639632717. The next prime is 639632753. The reversal of 639632748 is 847236936.

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

It is a junction number, because it is equal to n+sod(n) for n = 639632697 and 639632706.

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, 26651353 + ... + 26651376.

Almost surely, 2^639632748 is an apocalyptic number.

It is an amenable number.

639632748 is an abundant number, since it is smaller than the sum of its proper divisors (852843692).

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

639632748 is a wasteful number, since it uses less digits than its factorization.

639632748 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53302736 (or 53302734 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 48.

The square root of 639632748 is about 25290.9617847958. The cubic root of 639632748 is about 861.6090068795.

The spelling of 639632748 in words is "six hundred thirty-nine million, six hundred thirty-two thousand, seven hundred forty-eight".