138279162361 has 4 divisors (see below), whose sum is σ = 138329393652. Its totient is φ = 138228931072.

The previous prime is 138279162353. The next prime is 138279162367. The reversal of 138279162361 is 163261972831.

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 118459872400 + 19819289961 = 344180^2 + 140781^2 .

It is a cyclic number.

It is not a de Polignac number, because 138279162361 - 2³ = 138279162353 is a prime.

It is a super-2 number, since 2×138279162361² (a number of 23 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (49) 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 not an unprimeable number, because it can be changed into a prime (138279162367) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25111516 + ... + 25117021.

It is an arithmetic number, because the mean of its divisors is an integer number (34582348413).

Almost surely, 2^138279162361 is an apocalyptic number.

It is an amenable number.

138279162361 is a deficient number, since it is larger than the sum of its proper divisors (50231291).

138279162361 is an equidigital number, since it uses as much as digits as its factorization.

138279162361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50231290.

The product of its digits is 653184, while the sum is 49.

The spelling of 138279162361 in words is "one hundred thirty-eight billion, two hundred seventy-nine million, one hundred sixty-two thousand, three hundred sixty-one".