166943857 has 2 divisors, whose sum is σ = 166943858. Its totient is φ = 166943856.

The previous prime is 166943849. The next prime is 166943869. The reversal of 166943857 is 758349661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 138203536 + 28740321 = 11756^2 + 5361^2 .

It is an emirp because it is prime and its reverse (758349661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166943857 - 2³ = 166943849 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 166943857.

It is not a weakly prime, because it can be changed into another prime (166943957) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83471928 + 83471929.

It is an arithmetic number, because the mean of its divisors is an integer number (83471929).

Almost surely, 2^166943857 is an apocalyptic number.

It is an amenable number.

166943857 is a deficient number, since it is larger than the sum of its proper divisors (1).

166943857 is an equidigital number, since it uses as much as digits as its factorization.

166943857 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1088640, while the sum is 49.

The square root of 166943857 is about 12920.6755628334. The cubic root of 166943857 is about 550.6261266089.

The spelling of 166943857 in words is "one hundred sixty-six million, nine hundred forty-three thousand, eight hundred fifty-seven".