138888992 has 24 divisors (see below), whose sum is σ = 298296432. Its totient is φ = 63131200.

The previous prime is 138888989. The next prime is 138889001. The reversal of 138888992 is 299888831.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 196934 + ... + 197637.

It is an arithmetic number, because the mean of its divisors is an integer number (12429018).

Almost surely, 2^138888992 is an apocalyptic number.

It is an amenable number.

138888992 is an abundant number, since it is smaller than the sum of its proper divisors (159407440).

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

138888992 is a wasteful number, since it uses less digits than its factorization.

138888992 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 394592 (or 394584 counting only the distinct ones).

The product of its digits is 1990656, while the sum is 56.

The square root of 138888992 is about 11785.1173944089. The cubic root of 138888992 is about 517.8722124817.

The spelling of 138888992 in words is "one hundred thirty-eight million, eight hundred eighty-eight thousand, nine hundred ninety-two".