138899687 has 4 divisors (see below), whose sum is σ = 139026720. Its totient is φ = 138772656.

The previous prime is 138899669. The next prime is 138899689. The reversal of 138899687 is 786998831.

138899687 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 786998831 = 19219 ⋅40949.

It is a cyclic number.

It is not a de Polignac number, because 138899687 - 2¹² = 138895591 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138899689) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61862 + ... + 64067.

It is an arithmetic number, because the mean of its divisors is an integer number (34756680).

Almost surely, 2^138899687 is an apocalyptic number.

138899687 is a deficient number, since it is larger than the sum of its proper divisors (127033).

138899687 is a wasteful number, since it uses less digits than its factorization.

138899687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127032.

The product of its digits is 5225472, while the sum is 59.

The square root of 138899687 is about 11785.5711359272. The cubic root of 138899687 is about 517.8855048746.

The spelling of 138899687 in words is "one hundred thirty-eight million, eight hundred ninety-nine thousand, six hundred eighty-seven".