138479808685 has 4 divisors (see below), whose sum is σ = 166175770428. Its totient is φ = 110783846944.

The previous prime is 138479808679. The next prime is 138479808697. The reversal of 138479808685 is 586808974831.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 39960409801 + 98519398884 = 199901^2 + 313878^2 .

It is a cyclic number.

It is not a de Polignac number, because 138479808685 - 2⁵ = 138479808653 is a prime.

It is a Smith number, since the sum of its digits (67) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138479808685.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13847980864 + ... + 13847980873.

It is an arithmetic number, because the mean of its divisors is an integer number (41543942607).

Almost surely, 2^138479808685 is an apocalyptic number.

It is an amenable number.

138479808685 is a deficient number, since it is larger than the sum of its proper divisors (27695961743).

138479808685 is an equidigital number, since it uses as much as digits as its factorization.

138479808685 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27695961742.

The product of its (nonzero) digits is 92897280, while the sum is 67.

The spelling of 138479808685 in words is "one hundred thirty-eight billion, four hundred seventy-nine million, eight hundred eight thousand, six hundred eighty-five".