138018939 has 8 divisors (see below), whose sum is σ = 184207872. Its totient is φ = 91921320.

The previous prime is 138018919. The next prime is 138018953. The reversal of 138018939 is 939810831.

It is a happy number.

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

It is not a de Polignac number, because 138018939 - 2¹¹ = 138016891 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138018939.

It is not an unprimeable number, because it can be changed into a prime (138018919) 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 7 ways as a sum of consecutive naturals, for example, 19219 + ... + 25404.

It is an arithmetic number, because the mean of its divisors is an integer number (23025984).

Almost surely, 2^138018939 is an apocalyptic number.

138018939 is a deficient number, since it is larger than the sum of its proper divisors (46188933).

138018939 is a wasteful number, since it uses less digits than its factorization.

138018939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45657.

The product of its (nonzero) digits is 46656, while the sum is 42.

The square root of 138018939 is about 11748.1461941874. The cubic root of 138018939 is about 516.7885642780.

The spelling of 138018939 in words is "one hundred thirty-eight million, eighteen thousand, nine hundred thirty-nine".