138736931 has 8 divisors (see below), whose sum is σ = 139744464. Its totient is φ = 137733120.

The previous prime is 138736909. The next prime is 138736951. The reversal of 138736931 is 139637831.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138736931 is a prime.

It is a super-2 number, since 2×138736931² = 38495872046597522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138736901) 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, 141515 + ... + 142491.

It is an arithmetic number, because the mean of its divisors is an integer number (17468058).

Almost surely, 2^138736931 is an apocalyptic number.

138736931 is a deficient number, since it is larger than the sum of its proper divisors (1007533).

138736931 is an equidigital number, since it uses as much as digits as its factorization.

138736931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1861.

The product of its digits is 81648, while the sum is 41.

The square root of 138736931 is about 11778.6642281712. The cubic root of 138736931 is about 517.6831480073.

The spelling of 138736931 in words is "one hundred thirty-eight million, seven hundred thirty-six thousand, nine hundred thirty-one".