138694719638 has 4 divisors (see below), whose sum is σ = 208042079460. Its totient is φ = 69347359818.

The previous prime is 138694719637. The next prime is 138694719661. The reversal of 138694719638 is 836917496831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 836917496831 = 13 ⋅64378268987.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138694719637) 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, 34673679908 + ... + 34673679911.

It is an arithmetic number, because the mean of its divisors is an integer number (52010519865).

Almost surely, 2^138694719638 is an apocalyptic number.

138694719638 is a deficient number, since it is larger than the sum of its proper divisors (69347359822).

138694719638 is an equidigital number, since it uses as much as digits as its factorization.

138694719638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 69347359821.

The product of its digits is 47029248, while the sum is 65.

The spelling of 138694719638 in words is "one hundred thirty-eight billion, six hundred ninety-four million, seven hundred nineteen thousand, six hundred thirty-eight".