138138915 has 8 divisors (see below), whose sum is σ = 221022288. Its totient is φ = 73674080.

The previous prime is 138138899. The next prime is 138138967. The reversal of 138138915 is 519831831.

138138915 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 138138915 - 2⁴ = 138138899 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4604616 + ... + 4604645.

It is an arithmetic number, because the mean of its divisors is an integer number (27627786).

Almost surely, 2^138138915 is an apocalyptic number.

138138915 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

138138915 is a deficient number, since it is larger than the sum of its proper divisors (82883373).

138138915 is an equidigital number, since it uses as much as digits as its factorization.

138138915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9209269.

The product of its digits is 25920, while the sum is 39.

The square root of 138138915 is about 11753.2512523131. The cubic root of 138138915 is about 516.9382641871.

The spelling of 138138915 in words is "one hundred thirty-eight million, one hundred thirty-eight thousand, nine hundred fifteen".