161975161 has 2 divisors, whose sum is σ = 161975162. Its totient is φ = 161975160.

The previous prime is 161975153. The next prime is 161975189. The reversal of 161975161 is 161579161.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 142659136 + 19316025 = 11944^2 + 4395^2 .

It is a cyclic number.

It is not a de Polignac number, because 161975161 - 2³ = 161975153 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 161975161.

It is not a weakly prime, because it can be changed into another prime (161975111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80987580 + 80987581.

It is an arithmetic number, because the mean of its divisors is an integer number (80987581).

Almost surely, 2^161975161 is an apocalyptic number.

It is an amenable number.

161975161 is a deficient number, since it is larger than the sum of its proper divisors (1).

161975161 is an equidigital number, since it uses as much as digits as its factorization.

161975161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 11340, while the sum is 37.

The square root of 161975161 is about 12726.9462558777. The cubic root of 161975161 is about 545.1083150315.

The spelling of 161975161 in words is "one hundred sixty-one million, nine hundred seventy-five thousand, one hundred sixty-one".