138639184 has 10 divisors (see below), whose sum is σ = 268613450. Its totient is φ = 69319584.

The previous prime is 138639173. The next prime is 138639187. The reversal of 138639184 is 481936831.

It can be written as a sum of positive squares in only one way, i.e., 123210000 + 15429184 = 11100^2 + 3928^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 138639184.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138639187) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4332459 + ... + 4332490.

It is an arithmetic number, because the mean of its divisors is an integer number (26861345).

Almost surely, 2^138639184 is an apocalyptic number.

It is an amenable number.

138639184 is a deficient number, since it is larger than the sum of its proper divisors (129974266).

138639184 is an equidigital number, since it uses as much as digits as its factorization.

138639184 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8664957 (or 8664951 counting only the distinct ones).

The product of its digits is 124416, while the sum is 43.

The square root of 138639184 is about 11774.5141725678. The cubic root of 138639184 is about 517.5615416865.

The spelling of 138639184 in words is "one hundred thirty-eight million, six hundred thirty-nine thousand, one hundred eighty-four".