166661161 has 2 divisors, whose sum is σ = 166661162. Its totient is φ = 166661160.

The previous prime is 166661147. The next prime is 166661171. The reversal of 166661161 is 161166661.

166661161 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 133541136 + 33120025 = 11556^2 + 5755^2 .

It is a cyclic number.

It is not a de Polignac number, because 166661161 - 2⁵ = 166661129 is a prime.

It is not a weakly prime, because it can be changed into another prime (166661171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83330580 + 83330581.

It is an arithmetic number, because the mean of its divisors is an integer number (83330581).

Almost surely, 2^166661161 is an apocalyptic number.

It is an amenable number.

166661161 is a deficient number, since it is larger than the sum of its proper divisors (1).

166661161 is an equidigital number, since it uses as much as digits as its factorization.

166661161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 34.

The square root of 166661161 is about 12909.7312520439. The cubic root of 166661161 is about 550.3151483121.

The spelling of 166661161 in words is "one hundred sixty-six million, six hundred sixty-one thousand, one hundred sixty-one".