138870915 has 16 divisors (see below), whose sum is σ = 222393600. Its totient is φ = 73997792.

The previous prime is 138870899. The next prime is 138870929. The reversal of 138870915 is 519078831.

It is a cyclic number.

It is not a de Polignac number, because 138870915 - 2⁴ = 138870899 is a prime.

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, 16276 + ... + 23294.

It is an arithmetic number, because the mean of its divisors is an integer number (13899600).

Almost surely, 2^138870915 is an apocalyptic number.

138870915 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

138870915 is a deficient number, since it is larger than the sum of its proper divisors (83522685).

138870915 is a wasteful number, since it uses less digits than its factorization.

138870915 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8346.

The product of its (nonzero) digits is 60480, while the sum is 42.

The square root of 138870915 is about 11784.3504275798. The cubic root of 138870915 is about 517.8497437412.

The spelling of 138870915 in words is "one hundred thirty-eight million, eight hundred seventy thousand, nine hundred fifteen".