138888865 has 8 divisors (see below), whose sum is σ = 168142248. Its totient is φ = 110127360.

The previous prime is 138888857. The next prime is 138888907. The reversal of 138888865 is 568888831.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 7006609 + 131882256 = 2647^2 + 11484^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 138888865 - 2³ = 138888857 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 122346 + ... + 123475.

It is an arithmetic number, because the mean of its divisors is an integer number (21017781).

Almost surely, 2^138888865 is an apocalyptic number.

It is an amenable number.

138888865 is a deficient number, since it is larger than the sum of its proper divisors (29253383).

138888865 is a wasteful number, since it uses less digits than its factorization.

138888865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 245939.

The product of its digits is 2949120, while the sum is 55.

The square root of 138888865 is about 11785.1120062560. The cubic root of 138888865 is about 517.8720546343.

The spelling of 138888865 in words is "one hundred thirty-eight million, eight hundred eighty-eight thousand, eight hundred sixty-five".