138617839 has 2 divisors, whose sum is σ = 138617840. Its totient is φ = 138617838.

The previous prime is 138617837. The next prime is 138617861. The reversal of 138617839 is 938716831.

138617839 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 138617839 - 2¹ = 138617837 is a prime.

Together with 138617837, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138617837) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69308919 + 69308920.

It is an arithmetic number, because the mean of its divisors is an integer number (69308920).

Almost surely, 2^138617839 is an apocalyptic number.

138617839 is a deficient number, since it is larger than the sum of its proper divisors (1).

138617839 is an equidigital number, since it uses as much as digits as its factorization.

138617839 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 46.

The square root of 138617839 is about 11773.6077308529. The cubic root of 138617839 is about 517.5349789265.

The spelling of 138617839 in words is "one hundred thirty-eight million, six hundred seventeen thousand, eight hundred thirty-nine".