138915808 has 24 divisors (see below), whose sum is σ = 275495472. Its totient is φ = 68948736.

The previous prime is 138915787. The next prime is 138915827. The reversal of 138915808 is 808519831.

138915808 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11460 + ... + 20227.

It is an arithmetic number, because the mean of its divisors is an integer number (11478978).

Almost surely, 2^138915808 is an apocalyptic number.

It is an amenable number.

138915808 is a deficient number, since it is larger than the sum of its proper divisors (136579664).

138915808 is a wasteful number, since it uses less digits than its factorization.

138915808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31834 (or 31826 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 43.

The square root of 138915808 is about 11786.2550456029. The cubic root of 138915808 is about 517.9055397392.

The spelling of 138915808 in words is "one hundred thirty-eight million, nine hundred fifteen thousand, eight hundred eight".