166186961 has 2 divisors, whose sum is σ = 166186962. Its totient is φ = 166186960.

The previous prime is 166186957. The next prime is 166186967. The reversal of 166186961 is 169681661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 139972561 + 26214400 = 11831^2 + 5120^2 .

It is an emirp because it is prime and its reverse (169681661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166186961 - 2² = 166186957 is a prime.

It is not a weakly prime, because it can be changed into another prime (166186967) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83093480 + 83093481.

It is an arithmetic number, because the mean of its divisors is an integer number (83093481).

Almost surely, 2^166186961 is an apocalyptic number.

It is an amenable number.

166186961 is a deficient number, since it is larger than the sum of its proper divisors (1).

166186961 is an equidigital number, since it uses as much as digits as its factorization.

166186961 is an evil number, because the sum of its binary digits is even.

The product of its digits is 93312, while the sum is 44.

The square root of 166186961 is about 12891.3521788833. The cubic root of 166186961 is about 549.7927163793.

The spelling of 166186961 in words is "one hundred sixty-six million, one hundred eighty-six thousand, nine hundred sixty-one".