639031904320 has 112 divisors (see below), whose sum is σ = 1588197219840. Its totient is φ = 244446529536.

The previous prime is 639031904317. The next prime is 639031904321. The reversal of 639031904320 is 23409130936.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is not an unprimeable number, because it can be changed into a prime (639031904321) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 63460246 + ... + 63470314.

It is an arithmetic number, because the mean of its divisors is an integer number (14180332320).

Almost surely, 2^639031904320 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639031904320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (794098609920).

639031904320 is an abundant number, since it is smaller than the sum of its proper divisors (949165315520).

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

639031904320 is a wasteful number, since it uses less digits than its factorization.

639031904320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18732 (or 18722 counting only the distinct ones).

The product of its (nonzero) digits is 104976, while the sum is 40.

The spelling of 639031904320 in words is "six hundred thirty-nine billion, thirty-one million, nine hundred four thousand, three hundred twenty".