138438239 has 2 divisors, whose sum is σ = 138438240. Its totient is φ = 138438238.

The previous prime is 138438193. The next prime is 138438241. The reversal of 138438239 is 932834831.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 138438239 - 2¹² = 138434143 is a prime.

It is a super-2 number, since 2×138438239² = 38330292034842242, which contains 22 as substring.

Together with 138438241, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 138438196 and 138438205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138438299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69219119 + 69219120.

It is an arithmetic number, because the mean of its divisors is an integer number (69219120).

Almost surely, 2^138438239 is an apocalyptic number.

138438239 is a deficient number, since it is larger than the sum of its proper divisors (1).

138438239 is an equidigital number, since it uses as much as digits as its factorization.

138438239 is an evil number, because the sum of its binary digits is even.

The product of its digits is 124416, while the sum is 41.

The square root of 138438239 is about 11765.9780298962. The cubic root of 138438239 is about 517.3113678459.

The spelling of 138438239 in words is "one hundred thirty-eight million, four hundred thirty-eight thousand, two hundred thirty-nine".