138942915 has 32 divisors (see below), whose sum is σ = 242092800. Its totient is φ = 67777920.

The previous prime is 138942911. The next prime is 138942929. The reversal of 138942915 is 519249831.

It is not a de Polignac number, because 138942915 - 2² = 138942911 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138942911) 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, 141 + ... + 16670.

It is an arithmetic number, because the mean of its divisors is an integer number (7565400).

Almost surely, 2^138942915 is an apocalyptic number.

138942915 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

138942915 is a deficient number, since it is larger than the sum of its proper divisors (103149885).

138942915 is a wasteful number, since it uses less digits than its factorization.

138942915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16867.

The product of its digits is 77760, while the sum is 42.

The square root of 138942915 is about 11787.4049306877. The cubic root of 138942915 is about 517.9392242963.

The spelling of 138942915 in words is "one hundred thirty-eight million, nine hundred forty-two thousand, nine hundred fifteen".