161636161 has 2 divisors, whose sum is σ = 161636162. Its totient is φ = 161636160.

The previous prime is 161636147. The next prime is 161636171.

161636161 is nontrivially palindromic in base 10.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 138297600 + 23338561 = 11760^2 + 4831^2 .

It is a palprime.

It is a cyclic number.

It is not a de Polignac number, because 161636161 - 2⁵ = 161636129 is a prime.

It is a super-2 number, since 2×161636161² = 52252497085635842, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (161636141) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80818080 + 80818081.

It is an arithmetic number, because the mean of its divisors is an integer number (80818081).

Almost surely, 2^161636161 is an apocalyptic number.

It is an amenable number.

161636161 is a deficient number, since it is larger than the sum of its proper divisors (1).

161636161 is an equidigital number, since it uses as much as digits as its factorization.

161636161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3888, while the sum is 31.

The square root of 161636161 is about 12713.6210813442. The cubic root of 161636161 is about 544.7277612366.

The spelling of 161636161 in words is "one hundred sixty-one million, six hundred thirty-six thousand, one hundred sixty-one".