138873239 has 4 divisors (see below), whose sum is σ = 138900840. Its totient is φ = 138845640.

The previous prime is 138873181. The next prime is 138873253. The reversal of 138873239 is 932378831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 932378831 = 25847 ⋅36073.

It is a cyclic number.

It is not a de Polignac number, because 138873239 - 2²⁰ = 137824663 is a prime.

It is a super-2 number, since 2×138873239² = 38571553020702242, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138873239.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138873139) 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, 3872 + ... + 17109.

It is an arithmetic number, because the mean of its divisors is an integer number (34725210).

Almost surely, 2^138873239 is an apocalyptic number.

138873239 is a deficient number, since it is larger than the sum of its proper divisors (27601).

138873239 is an equidigital number, since it uses as much as digits as its factorization.

138873239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27600.

The product of its digits is 217728, while the sum is 44.

The square root of 138873239 is about 11784.4490325174. The cubic root of 138873239 is about 517.8526324576.

The spelling of 138873239 in words is "one hundred thirty-eight million, eight hundred seventy-three thousand, two hundred thirty-nine".