166065961 has 2 divisors, whose sum is σ = 166065962. Its totient is φ = 166065960.

The previous prime is 166065929. The next prime is 166065971. The reversal of 166065961 is 169560661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 89415936 + 76650025 = 9456^2 + 8755^2 .

It is an emirp because it is prime and its reverse (169560661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166065961 - 2⁵ = 166065929 is a prime.

It is not a weakly prime, because it can be changed into another prime (166065971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83032980 + 83032981.

It is an arithmetic number, because the mean of its divisors is an integer number (83032981).

Almost surely, 2^166065961 is an apocalyptic number.

It is an amenable number.

166065961 is a deficient number, since it is larger than the sum of its proper divisors (1).

166065961 is an equidigital number, since it uses as much as digits as its factorization.

166065961 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 58320, while the sum is 40.

The square root of 166065961 is about 12886.6582557310. The cubic root of 166065961 is about 549.6592500906.

The spelling of 166065961 in words is "one hundred sixty-six million, sixty-five thousand, nine hundred sixty-one".