138987942 has 64 divisors (see below), whose sum is σ = 305565696. Its totient is φ = 42007680.

The previous prime is 138987931. The next prime is 138987943. The reversal of 138987942 is 249789831.

138987942 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138987943) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 226428 + ... + 227040.

It is an arithmetic number, because the mean of its divisors is an integer number (4774464).

Almost surely, 2^138987942 is an apocalyptic number.

138987942 is an abundant number, since it is smaller than the sum of its proper divisors (166577754).

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

138987942 is a wasteful number, since it uses less digits than its factorization.

138987942 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 725.

The product of its digits is 870912, while the sum is 51.

The square root of 138987942 is about 11789.3147383552. The cubic root of 138987942 is about 517.9951674887.

The spelling of 138987942 in words is "one hundred thirty-eight million, nine hundred eighty-seven thousand, nine hundred forty-two".