639938259 has 32 divisors (see below), whose sum is σ = 1056672000. Its totient is φ = 380391552.

The previous prime is 639938227. The next prime is 639938261. The reversal of 639938259 is 952839936.

639938259 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 639938259 - 2⁵ = 639938227 is a prime.

It is not an unprimeable number, because it can be changed into a prime (639938219) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27969 + ... + 45410.

It is an arithmetic number, because the mean of its divisors is an integer number (33021000).

Almost surely, 2^639938259 is an apocalyptic number.

639938259 is a deficient number, since it is larger than the sum of its proper divisors (416733741).

639938259 is a wasteful number, since it uses less digits than its factorization.

639938259 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73424 (or 73418 counting only the distinct ones).

The product of its digits is 3149280, while the sum is 54.

The square root of 639938259 is about 25297.0009882595. Note that the first 3 decimals coincide. The cubic root of 639938259 is about 861.7461632565.

The spelling of 639938259 in words is "six hundred thirty-nine million, nine hundred thirty-eight thousand, two hundred fifty-nine".