138213188 has 24 divisors (see below), whose sum is σ = 254945880. Its totient is φ = 65461760.

The previous prime is 138213181. The next prime is 138213191. The reversal of 138213188 is 881312831.

138213188 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 6927424 + 131285764 = 2632^2 + 11458^2 .

It is not an unprimeable number, because it can be changed into a prime (138213181) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5093 + ... + 17388.

It is an arithmetic number, because the mean of its divisors is an integer number (10622745).

Almost surely, 2^138213188 is an apocalyptic number.

It is an amenable number.

138213188 is a deficient number, since it is larger than the sum of its proper divisors (116732692).

138213188 is a wasteful number, since it uses less digits than its factorization.

138213188 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22567 (or 22565 counting only the distinct ones).

The product of its digits is 9216, while the sum is 35.

The square root of 138213188 is about 11756.4105066130. The cubic root of 138213188 is about 517.0308947987.

The spelling of 138213188 in words is "one hundred thirty-eight million, two hundred thirteen thousand, one hundred eighty-eight".