138231239 has 2 divisors, whose sum is σ = 138231240. Its totient is φ = 138231238.

The previous prime is 138231229. The next prime is 138231319. The reversal of 138231239 is 932132831.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138231239 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138231229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69115619 + 69115620.

It is an arithmetic number, because the mean of its divisors is an integer number (69115620).

Almost surely, 2^138231239 is an apocalyptic number.

138231239 is a deficient number, since it is larger than the sum of its proper divisors (1).

138231239 is an equidigital number, since it uses as much as digits as its factorization.

138231239 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 32.

The square root of 138231239 is about 11757.1781903652. The cubic root of 138231239 is about 517.0534023431.

The spelling of 138231239 in words is "one hundred thirty-eight million, two hundred thirty-one thousand, two hundred thirty-nine".