166643173 has 2 divisors, whose sum is σ = 166643174. Its totient is φ = 166643172.

The previous prime is 166643149. The next prime is 166643179. The reversal of 166643173 is 371346661.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 118853604 + 47789569 = 10902^2 + 6913^2 .

It is a cyclic number.

It is not a de Polignac number, because 166643173 - 2⁹ = 166642661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166643179) 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, 83321586 + 83321587.

It is an arithmetic number, because the mean of its divisors is an integer number (83321587).

Almost surely, 2^166643173 is an apocalyptic number.

It is an amenable number.

166643173 is a deficient number, since it is larger than the sum of its proper divisors (1).

166643173 is an equidigital number, since it uses as much as digits as its factorization.

166643173 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54432, while the sum is 37.

The square root of 166643173 is about 12909.0345494928. The cubic root of 166643173 is about 550.2953488080.

The spelling of 166643173 in words is "one hundred sixty-six million, six hundred forty-three thousand, one hundred seventy-three".