166163644541 has 2 divisors, whose sum is σ = 166163644542. Its totient is φ = 166163644540.

The previous prime is 166163644489. The next prime is 166163644589. The reversal of 166163644541 is 145446361661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 164170022041 + 1993622500 = 405179^2 + 44650^2 .

It is a cyclic number.

It is not a de Polignac number, because 166163644541 - 2¹⁴ = 166163628157 is a prime.

It is a super-2 number, since 2×166163644541² (a number of 23 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166163644441) 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, 83081822270 + 83081822271.

It is an arithmetic number, because the mean of its divisors is an integer number (83081822271).

Almost surely, 2^166163644541 is an apocalyptic number.

It is an amenable number.

166163644541 is a deficient number, since it is larger than the sum of its proper divisors (1).

166163644541 is an equidigital number, since it uses as much as digits as its factorization.

166163644541 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1244160, while the sum is 47.

The spelling of 166163644541 in words is "one hundred sixty-six billion, one hundred sixty-three million, six hundred forty-four thousand, five hundred forty-one".