138113171861 has 4 divisors (see below), whose sum is σ = 157843624992. Its totient is φ = 118382718732.

The previous prime is 138113171857. The next prime is 138113171869. The reversal of 138113171861 is 168171311831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 168171311831 = 199 ⋅845081969.

It is a cyclic number.

It is not a de Polignac number, because 138113171861 - 2² = 138113171857 is a prime.

It is a super-2 number, since 2×138113171861² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138113171869) 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, 9865226555 + ... + 9865226568.

It is an arithmetic number, because the mean of its divisors is an integer number (39460906248).

Almost surely, 2^138113171861 is an apocalyptic number.

It is an amenable number.

138113171861 is a deficient number, since it is larger than the sum of its proper divisors (19730453131).

138113171861 is an equidigital number, since it uses as much as digits as its factorization.

138113171861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19730453130.

The product of its digits is 24192, while the sum is 41.

The spelling of 138113171861 in words is "one hundred thirty-eight billion, one hundred thirteen million, one hundred seventy-one thousand, eight hundred sixty-one".