138615917 has 8 divisors (see below), whose sum is σ = 157792320. Its totient is φ = 120535360.

The previous prime is 138615913. The next prime is 138615929. The reversal of 138615917 is 719516831.

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

It is not a de Polignac number, because 138615917 - 2² = 138615913 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138615913) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 273692 + ... + 274197.

It is an arithmetic number, because the mean of its divisors is an integer number (19724040).

Almost surely, 2^138615917 is an apocalyptic number.

It is an amenable number.

138615917 is a deficient number, since it is larger than the sum of its proper divisors (19176403).

138615917 is a wasteful number, since it uses less digits than its factorization.

138615917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 547923.

The product of its digits is 45360, while the sum is 41.

The square root of 138615917 is about 11773.5261073308. The cubic root of 138615917 is about 517.5325869621.

The spelling of 138615917 in words is "one hundred thirty-eight million, six hundred fifteen thousand, nine hundred seventeen".