138815912 has 16 divisors (see below), whose sum is σ = 260439840. Its totient is φ = 69365296.

The previous prime is 138815899. The next prime is 138815933. The reversal of 138815912 is 219518831.

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, 11693 + ... + 20355.

It is an arithmetic number, because the mean of its divisors is an integer number (16277490).

Almost surely, 2^138815912 is an apocalyptic number.

It is an amenable number.

138815912 is a deficient number, since it is larger than the sum of its proper divisors (121623928).

138815912 is a wasteful number, since it uses less digits than its factorization.

138815912 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10672 (or 10668 counting only the distinct ones).

The product of its digits is 17280, while the sum is 38.

The square root of 138815912 is about 11782.0164657838. The cubic root of 138815912 is about 517.7813659704.

The spelling of 138815912 in words is "one hundred thirty-eight million, eight hundred fifteen thousand, nine hundred twelve".