166851864589 has 2 divisors, whose sum is σ = 166851864590. Its totient is φ = 166851864588.

The previous prime is 166851864563. The next prime is 166851864623. The reversal of 166851864589 is 985468158661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 147097562089 + 19754302500 = 383533^2 + 140550^2 .

It is a cyclic number.

It is not a de Polignac number, because 166851864589 - 2²¹ = 166849767437 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166851864089) 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, 83425932294 + 83425932295.

It is an arithmetic number, because the mean of its divisors is an integer number (83425932295).

Almost surely, 2^166851864589 is an apocalyptic number.

It is an amenable number.

166851864589 is a deficient number, since it is larger than the sum of its proper divisors (1).

166851864589 is an equidigital number, since it uses as much as digits as its factorization.

166851864589 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 99532800, while the sum is 67.

The spelling of 166851864589 in words is "one hundred sixty-six billion, eight hundred fifty-one million, eight hundred sixty-four thousand, five hundred eighty-nine".