138216836 has 12 divisors (see below), whose sum is σ = 245286720. Its totient is φ = 68134920.

The previous prime is 138216803. The next prime is 138216839. The reversal of 138216836 is 638612831.

It is a self number, because there is not a number n which added to its sum of digits gives 138216836.

It is not an unprimeable number, because it can be changed into a prime (138216839) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 243056 + ... + 243623.

It is an arithmetic number, because the mean of its divisors is an integer number (20440560).

Almost surely, 2^138216836 is an apocalyptic number.

It is an amenable number.

138216836 is a deficient number, since it is larger than the sum of its proper divisors (107069884).

138216836 is a wasteful number, since it uses less digits than its factorization.

138216836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 486754 (or 486752 counting only the distinct ones).

The product of its digits is 41472, while the sum is 38.

The square root of 138216836 is about 11756.5656549862. The cubic root of 138216836 is about 517.0354435979.

The spelling of 138216836 in words is "one hundred thirty-eight million, two hundred sixteen thousand, eight hundred thirty-six".