138577931 has 8 divisors (see below), whose sum is σ = 147068784. Its totient is φ = 130124800.

The previous prime is 138577927. The next prime is 138577937. The reversal of 138577931 is 139775831.

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

It is not a de Polignac number, because 138577931 - 2² = 138577927 is a prime.

It is a super-2 number, since 2×138577931² = 38407685920481522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138577937) 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, 1670 + ... + 16731.

It is an arithmetic number, because the mean of its divisors is an integer number (18383598).

Almost surely, 2^138577931 is an apocalyptic number.

138577931 is a deficient number, since it is larger than the sum of its proper divisors (8490853).

138577931 is a wasteful number, since it uses less digits than its factorization.

138577931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18861.

The product of its digits is 158760, while the sum is 44.

The square root of 138577931 is about 11771.9128012401. The cubic root of 138577931 is about 517.4853081471.

The spelling of 138577931 in words is "one hundred thirty-eight million, five hundred seventy-seven thousand, nine hundred thirty-one".