138888765 has 48 divisors (see below), whose sum is σ = 257662080. Its totient is φ = 68999040.

The previous prime is 138888707. The next prime is 138888767. The reversal of 138888765 is 567888831.

It is a happy number.

It is not a de Polignac number, because 138888765 - 2¹⁰ = 138887741 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138888767) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 50824 + ... + 53486.

It is an arithmetic number, because the mean of its divisors is an integer number (5367960).

Almost surely, 2^138888765 is an apocalyptic number.

138888765 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

138888765 is a deficient number, since it is larger than the sum of its proper divisors (118773315).

138888765 is a wasteful number, since it uses less digits than its factorization.

138888765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2754 (or 2751 counting only the distinct ones).

The product of its digits is 2580480, while the sum is 54.

The square root of 138888765 is about 11785.1077636142. The cubic root of 138888765 is about 517.8719303450.

The spelling of 138888765 in words is "one hundred thirty-eight million, eight hundred eighty-eight thousand, seven hundred sixty-five".