166557197 has 2 divisors, whose sum is σ = 166557198. Its totient is φ = 166557196.

The previous prime is 166557187. The next prime is 166557227. The reversal of 166557197 is 791755661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 132112036 + 34445161 = 11494^2 + 5869^2 .

It is a cyclic number.

It is not a de Polignac number, because 166557197 - 2⁶ = 166557133 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166557107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83278598 + 83278599.

It is an arithmetic number, because the mean of its divisors is an integer number (83278599).

Almost surely, 2^166557197 is an apocalyptic number.

It is an amenable number.

166557197 is a deficient number, since it is larger than the sum of its proper divisors (1).

166557197 is an equidigital number, since it uses as much as digits as its factorization.

166557197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 396900, while the sum is 47.

The square root of 166557197 is about 12905.7040489855. The cubic root of 166557197 is about 550.2006948017.

The spelling of 166557197 in words is "one hundred sixty-six million, five hundred fifty-seven thousand, one hundred ninety-seven".