138931061939 has 2 divisors, whose sum is σ = 138931061940. Its totient is φ = 138931061938.

The previous prime is 138931061897. The next prime is 138931061959. The reversal of 138931061939 is 939160139831.

138931061939 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 138931061939 - 2¹⁶ = 138930996403 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (138931061959) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69465530969 + 69465530970.

It is an arithmetic number, because the mean of its divisors is an integer number (69465530970).

Almost surely, 2^138931061939 is an apocalyptic number.

138931061939 is a deficient number, since it is larger than the sum of its proper divisors (1).

138931061939 is an equidigital number, since it uses as much as digits as its factorization.

138931061939 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 944784, while the sum is 53.

The spelling of 138931061939 in words is "one hundred thirty-eight billion, nine hundred thirty-one million, sixty-one thousand, nine hundred thirty-nine".