138188664 has 24 divisors (see below), whose sum is σ = 374261160. Its totient is φ = 46062864.

The previous prime is 138188651. The next prime is 138188671. The reversal of 138188664 is 466881831.

It is a happy number.

138188664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (24).

It is a super-2 number, since 2×138188664² = 38192213716209792, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 959572 + ... + 959715.

It is an arithmetic number, because the mean of its divisors is an integer number (15594215).

Almost surely, 2^138188664 is an apocalyptic number.

It is an amenable number.

138188664 is an abundant number, since it is smaller than the sum of its proper divisors (236072496).

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

138188664 is a wasteful number, since it uses less digits than its factorization.

138188664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1919299 (or 1919292 counting only the distinct ones).

The product of its digits is 221184, while the sum is 45.

The square root of 138188664 is about 11755.3674549118. The cubic root of 138188664 is about 517.0003130193. Note that the first 3 decimals are identical.

The spelling of 138188664 in words is "one hundred thirty-eight million, one hundred eighty-eight thousand, six hundred sixty-four".