161822161 has 2 divisors, whose sum is σ = 161822162. Its totient is φ = 161822160.

The previous prime is 161822159. The next prime is 161822179. The reversal of 161822161 is 161228161.

161822161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 126787600 + 35034561 = 11260^2 + 5919^2 .

It is a cyclic number.

It is not a de Polignac number, because 161822161 - 2¹ = 161822159 is a prime.

Together with 161822159, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (161822761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80911080 + 80911081.

It is an arithmetic number, because the mean of its divisors is an integer number (80911081).

Almost surely, 2^161822161 is an apocalyptic number.

It is an amenable number.

161822161 is a deficient number, since it is larger than the sum of its proper divisors (1).

161822161 is an equidigital number, since it uses as much as digits as its factorization.

161822161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1152, while the sum is 28.

The square root of 161822161 is about 12720.9339672840. The cubic root of 161822161 is about 544.9366264723.

The spelling of 161822161 in words is "one hundred sixty-one million, eight hundred twenty-two thousand, one hundred sixty-one".