138515845123 has 4 divisors (see below), whose sum is σ = 139289676840. Its totient is φ = 137742013408.

The previous prime is 138515845087. The next prime is 138515845129. The reversal of 138515845123 is 321548515831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 321548515831 = 113 ⋅2845562087.

It is a cyclic number.

It is not a de Polignac number, because 138515845123 - 2²⁵ = 138482290691 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138515845129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 386915590 + ... + 386915947.

It is an arithmetic number, because the mean of its divisors is an integer number (34822419210).

Almost surely, 2^138515845123 is an apocalyptic number.

138515845123 is a deficient number, since it is larger than the sum of its proper divisors (773831717).

138515845123 is an equidigital number, since it uses as much as digits as its factorization.

138515845123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 773831716.

The product of its digits is 576000, while the sum is 46.

The spelling of 138515845123 in words is "one hundred thirty-eight billion, five hundred fifteen million, eight hundred forty-five thousand, one hundred twenty-three".