168108209189 has 4 divisors (see below), whose sum is σ = 168430874220. Its totient is φ = 167785544160.

The previous prime is 168108209173. The next prime is 168108209197. The reversal of 168108209189 is 981902801861.

It is a happy number.

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 66637292164 + 101470917025 = 258142^2 + 318545^2 .

It is a cyclic number.

It is not a de Polignac number, because 168108209189 - 2⁴ = 168108209173 is a prime.

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 168108209189.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (168108209149) 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, 161331734 + ... + 161332775.

It is an arithmetic number, because the mean of its divisors is an integer number (42107718555).

Almost surely, 2^168108209189 is an apocalyptic number.

It is an amenable number.

168108209189 is a deficient number, since it is larger than the sum of its proper divisors (322665031).

168108209189 is an equidigital number, since it uses as much as digits as its factorization.

168108209189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322665030.

The product of its (nonzero) digits is 497664, while the sum is 53.

The spelling of 168108209189 in words is "one hundred sixty-eight billion, one hundred eight million, two hundred nine thousand, one hundred eighty-nine".