138928920 has 64 divisors (see below), whose sum is σ = 448852320. Its totient is φ = 34197504.

The previous prime is 138928891. The next prime is 138928939. The reversal of 138928920 is 29829831.

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, 42969 + ... + 46088.

Almost surely, 2^138928920 is an apocalyptic number.

138928920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

138928920 is an abundant number, since it is smaller than the sum of its proper divisors (309923400).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

138928920 is a wasteful number, since it uses less digits than its factorization.

138928920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89084 (or 89080 counting only the distinct ones).

The product of its (nonzero) digits is 62208, while the sum is 42.

The square root of 138928920 is about 11786.8112736227. The cubic root of 138928920 is about 517.9218339341.

The spelling of 138928920 in words is "one hundred thirty-eight million, nine hundred twenty-eight thousand, nine hundred twenty".