138818239 has 8 divisors (see below), whose sum is σ = 159899648. Its totient is φ = 118049400.

The previous prime is 138818219. The next prime is 138818261. The reversal of 138818239 is 932818831.

138818239 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 138818239 - 2⁷ = 138818111 is a prime.

It is a super-2 number, since 2×138818239² = 38541006958122242, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 138818195 and 138818204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138818219) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 77187 + ... + 78964.

It is an arithmetic number, because the mean of its divisors is an integer number (19987456).

Almost surely, 2^138818239 is an apocalyptic number.

138818239 is a deficient number, since it is larger than the sum of its proper divisors (21081409).

138818239 is a wasteful number, since it uses less digits than its factorization.

138818239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 156285.

The product of its digits is 82944, while the sum is 43.

The square root of 138818239 is about 11782.1152175660. The cubic root of 138818239 is about 517.7842591798.

The spelling of 138818239 in words is "one hundred thirty-eight million, eight hundred eighteen thousand, two hundred thirty-nine".