138639850 has 24 divisors (see below), whose sum is σ = 258920928. Its totient is φ = 55230000.

The previous prime is 138639847. The next prime is 138639859. The reversal of 138639850 is 58936831.

138639850 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 138639797 and 138639806.

It is not an unprimeable number, because it can be changed into a prime (138639859) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7027 + ... + 18073.

It is an arithmetic number, because the mean of its divisors is an integer number (10788372).

Almost surely, 2^138639850 is an apocalyptic number.

138639850 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

138639850 is a deficient number, since it is larger than the sum of its proper divisors (120281078).

138639850 is a wasteful number, since it uses less digits than its factorization.

138639850 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11310 (or 11305 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 43.

The square root of 138639850 is about 11774.5424539555. The cubic root of 138639850 is about 517.5623704456.

The spelling of 138639850 in words is "one hundred thirty-eight million, six hundred thirty-nine thousand, eight hundred fifty".