639042432 has 128 divisors (see below), whose sum is σ = 2002790400. Its totient is φ = 176670720.

The previous prime is 639042431. The next prime is 639042457. The reversal of 639042432 is 234240936.

It is a tau number, because it is divible by the number of its divisors (128).

It is a junction number, because it is equal to n+sod(n) for n = 639042393 and 639042402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639042431) 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, 79494 + ... + 87162.

It is an arithmetic number, because the mean of its divisors is an integer number (15646800).

Almost surely, 2^639042432 is an apocalyptic number.

639042432 is a gapful number since it is divisible by the number (62) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639042432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1001395200).

639042432 is an abundant number, since it is smaller than the sum of its proper divisors (1363747968).

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

639042432 is a wasteful number, since it uses less digits than its factorization.

639042432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7724 (or 7712 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 33.

The square root of 639042432 is about 25279.2885975852. The cubic root of 639042432 is about 861.3438661234.

The spelling of 639042432 in words is "six hundred thirty-nine million, forty-two thousand, four hundred thirty-two".