639520135 has 16 divisors (see below), whose sum is σ = 772290432. Its totient is φ = 508384800.

The previous prime is 639520097. The next prime is 639520169. The reversal of 639520135 is 531025936.

It is a happy number.

639520135 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 639520135 - 2¹⁷ = 639389063 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 639520135.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 812212 + ... + 812998.

It is an arithmetic number, because the mean of its divisors is an integer number (48268152).

Almost surely, 2^639520135 is an apocalyptic number.

639520135 is a deficient number, since it is larger than the sum of its proper divisors (132770297).

639520135 is a wasteful number, since it uses less digits than its factorization.

639520135 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1614.

The product of its (nonzero) digits is 24300, while the sum is 34.

The square root of 639520135 is about 25288.7353380908. The cubic root of 639520135 is about 861.5584392842.

The spelling of 639520135 in words is "six hundred thirty-nine million, five hundred twenty thousand, one hundred thirty-five".