639289020 has 24 divisors (see below), whose sum is σ = 1790009424. Its totient is φ = 170477056.

The previous prime is 639289003. The next prime is 639289031. The reversal of 639289020 is 20982936.

639289020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 639289020.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5327349 + ... + 5327468.

It is an arithmetic number, because the mean of its divisors is an integer number (74583726).

Almost surely, 2^639289020 is an apocalyptic number.

639289020 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

639289020 is an abundant number, since it is smaller than the sum of its proper divisors (1150720404).

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

639289020 is a wasteful number, since it uses less digits than its factorization.

639289020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10654829 (or 10654827 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 39.

The square root of 639289020 is about 25284.1654005031. The cubic root of 639289020 is about 861.4546411086.

The spelling of 639289020 in words is "six hundred thirty-nine million, two hundred eighty-nine thousand, twenty".