138939 has 8 divisors (see below), whose sum is σ = 191760. Its totient is φ = 89376.

The previous prime is 138937. The next prime is 138959. The reversal of 138939 is 939831.

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

It is not a de Polignac number, because 138939 - 2¹ = 138937 is a prime.

It is not an unprimeable number, because it can be changed into a prime (138937) 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, 712 + ... + 885.

It is an arithmetic number, because the mean of its divisors is an integer number (23970).

2¹³⁸⁹³⁹ is an apocalyptic number.

138939 is a deficient number, since it is larger than the sum of its proper divisors (52821).

138939 is a wasteful number, since it uses less digits than its factorization.

138939 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1629.

The product of its digits is 5832, while the sum is 33.

The square root of 138939 is about 372.7452212973. The cubic root of 138939 is about 51.7934359586.

The spelling of 138939 in words is "one hundred thirty-eight thousand, nine hundred thirty-nine".