138239719 has 2 divisors, whose sum is σ = 138239720. Its totient is φ = 138239718.

The previous prime is 138239681. The next prime is 138239747. The reversal of 138239719 is 917932831.

It is a strong prime.

It is an emirp because it is prime and its reverse (917932831) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138239719 is a prime.

It is a super-2 number, since 2×138239719² = 38220439818397922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138239779) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69119859 + 69119860.

It is an arithmetic number, because the mean of its divisors is an integer number (69119860).

Almost surely, 2^138239719 is an apocalyptic number.

138239719 is a deficient number, since it is larger than the sum of its proper divisors (1).

138239719 is an equidigital number, since it uses as much as digits as its factorization.

138239719 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81648, while the sum is 43.

The square root of 138239719 is about 11757.5388155855. The cubic root of 138239719 is about 517.0639752624.

The spelling of 138239719 in words is "one hundred thirty-eight million, two hundred thirty-nine thousand, seven hundred nineteen".