639442634 has 16 divisors (see below), whose sum is σ = 992908800. Its totient is φ = 308487984.

The previous prime is 639442627. The next prime is 639442667. The reversal of 639442634 is 436244936.

639442634 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 639442591 and 639442600.

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, 115559 + ... + 120965.

It is an arithmetic number, because the mean of its divisors is an integer number (62056800).

Almost surely, 2^639442634 is an apocalyptic number.

639442634 is a deficient number, since it is larger than the sum of its proper divisors (353466166).

639442634 is a wasteful number, since it uses less digits than its factorization.

639442634 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7477.

The product of its digits is 373248, while the sum is 41.

The square root of 639442634 is about 25287.2029690909. The cubic root of 639442634 is about 861.5236348872.

The spelling of 639442634 in words is "six hundred thirty-nine million, four hundred forty-two thousand, six hundred thirty-four".