639748912 has 40 divisors (see below), whose sum is σ = 1385192592. Its totient is φ = 283699200.

The previous prime is 639748877. The next prime is 639748919. The reversal of 639748912 is 219847936.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (639748919) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 37113 + ... + 51544.

Almost surely, 2^639748912 is an apocalyptic number.

It is an amenable number.

639748912 is an abundant number, since it is smaller than the sum of its proper divisors (745443680).

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

639748912 is a wasteful number, since it uses less digits than its factorization.

639748912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88717 (or 88711 counting only the distinct ones).

The product of its digits is 653184, while the sum is 49.

The square root of 639748912 is about 25293.2582321851. The cubic root of 639748912 is about 861.6611627928.

The spelling of 639748912 in words is "six hundred thirty-nine million, seven hundred forty-eight thousand, nine hundred twelve".