138891836 has 24 divisors (see below), whose sum is σ = 258342336. Its totient is φ = 65111040.

The previous prime is 138891829. The next prime is 138891847. The reversal of 138891836 is 638198831.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14660 + ... + 22196.

It is an arithmetic number, because the mean of its divisors is an integer number (10764264).

Almost surely, 2^138891836 is an apocalyptic number.

It is an amenable number.

138891836 is a deficient number, since it is larger than the sum of its proper divisors (119450500).

138891836 is a wasteful number, since it uses less digits than its factorization.

138891836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7829 (or 7827 counting only the distinct ones).

The product of its digits is 248832, while the sum is 47.

The square root of 138891836 is about 11785.2380544476. The cubic root of 138891836 is about 517.8757472435.

The spelling of 138891836 in words is "one hundred thirty-eight million, eight hundred ninety-one thousand, eight hundred thirty-six".