161261315161 has 4 divisors (see below), whose sum is σ = 161262373300. Its totient is φ = 161260257024.

The previous prime is 161261315147. The next prime is 161261315183. The reversal of 161261315161 is 161513162161.

161261315161 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 a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 25734255561 + 135527059600 = 160419^2 + 368140^2 .

It is a cyclic number.

It is not a de Polignac number, because 161261315161 - 2¹⁷ = 161261184089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (161261315191) 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, 252156 + ... + 621373.

It is an arithmetic number, because the mean of its divisors is an integer number (40315593325).

Almost surely, 2^161261315161 is an apocalyptic number.

It is an amenable number.

161261315161 is a deficient number, since it is larger than the sum of its proper divisors (1058139).

161261315161 is an equidigital number, since it uses as much as digits as its factorization.

161261315161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1058138.

The product of its digits is 6480, while the sum is 34.

The spelling of 161261315161 in words is "one hundred sixty-one billion, two hundred sixty-one million, three hundred fifteen thousand, one hundred sixty-one".