91668173 has 2 divisors, whose sum is σ = 91668174. Its totient is φ = 91668172.

The previous prime is 91668163. The next prime is 91668193. The reversal of 91668173 is 37186619.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75811849 + 15856324 = 8707^2 + 3982^2 .

It is a cyclic number.

It is not a de Polignac number, because 91668173 - 2¹⁴ = 91651789 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91668173.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (91668113) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 45834086 + 45834087.

It is an arithmetic number, because the mean of its divisors is an integer number (45834087).

Almost surely, 2^91668173 is an apocalyptic number.

It is an amenable number.

91668173 is a deficient number, since it is larger than the sum of its proper divisors (1).

91668173 is an equidigital number, since it uses as much as digits as its factorization.

91668173 is an evil number, because the sum of its binary digits is even.

The product of its digits is 54432, while the sum is 41.

The square root of 91668173 is about 9574.3497429329. The cubic root of 91668173 is about 450.8923412691.

The spelling of 91668173 in words is "ninety-one million, six hundred sixty-eight thousand, one hundred seventy-three".