138973638 has 32 divisors (see below), whose sum is σ = 293126400. Its totient is φ = 43803936.

The previous prime is 138973621. The next prime is 138973643. The reversal of 138973638 is 836379831.

138973638 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Curzon number.

It is a congruent number.

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, 94920 + ... + 96372.

It is an arithmetic number, because the mean of its divisors is an integer number (9160200).

Almost surely, 2^138973638 is an apocalyptic number.

138973638 is an abundant number, since it is smaller than the sum of its proper divisors (154152762).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

138973638 is a wasteful number, since it uses less digits than its factorization.

138973638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2316.

The product of its digits is 653184, while the sum is 48.

The square root of 138973638 is about 11788.7080717100. The cubic root of 138973638 is about 517.9773969853.

The spelling of 138973638 in words is "one hundred thirty-eight million, nine hundred seventy-three thousand, six hundred thirty-eight".