168165668161 has 4 divisors (see below), whose sum is σ = 168167262852. Its totient is φ = 168164073472.

The previous prime is 168165668129. The next prime is 168165668171. The reversal of 168165668161 is 161866561861.

168165668161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 161866561861 = 109 ⋅1485014329.

It can be written as a sum of positive squares in 2 ways, for example, as 128840795136 + 39324873025 = 358944^2 + 198305^2 .

It is a cyclic number.

It is not a de Polignac number, because 168165668161 - 2⁵ = 168165668129 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (168165668171) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 627040 + ... + 854113.

It is an arithmetic number, because the mean of its divisors is an integer number (42041815713).

Almost surely, 2^168165668161 is an apocalyptic number.

It is an amenable number.

168165668161 is a deficient number, since it is larger than the sum of its proper divisors (1594691).

168165668161 is a wasteful number, since it uses less digits than its factorization.

168165668161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1594690.

The product of its digits is 2488320, while the sum is 55.

The spelling of 168165668161 in words is "one hundred sixty-eight billion, one hundred sixty-five million, six hundred sixty-eight thousand, one hundred sixty-one".