161321123161 has 16 divisors (see below), whose sum is σ = 190672308288. Its totient is φ = 134818790400.

The previous prime is 161321123153. The next prime is 161321123203.

161321123161 is nontrivially palindromic in base 10.

It is a cyclic number.

It is not a de Polignac number, because 161321123161 - 2³ = 161321123153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (161321123261) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10023120 + ... + 10039201.

It is an arithmetic number, because the mean of its divisors is an integer number (11917019268).

Almost surely, 2^161321123161 is an apocalyptic number.

161321123161 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

161321123161 is a deficient number, since it is larger than the sum of its proper divisors (29351185127).

161321123161 is a wasteful number, since it uses less digits than its factorization.

161321123161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20062392.

The product of its digits is 1296, while the sum is 28.

It can be divided in two parts, 161321 and 123161, that added together give a palindrome (284482).

The spelling of 161321123161 in words is "one hundred sixty-one billion, three hundred twenty-one million, one hundred twenty-three thousand, one hundred sixty-one".