166698009 has 12 divisors (see below), whose sum is σ = 241265700. Its totient is φ = 110910624.

The previous prime is 166697969. The next prime is 166698011. The reversal of 166698009 is 900896661.

It can be written as a sum of positive squares in 2 ways, for example, as 150921225 + 15776784 = 12285^2 + 3972^2 .

It is not a de Polignac number, because 166698009 - 2⁹ = 166697497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (166698109) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13614 + ... + 22775.

It is an arithmetic number, because the mean of its divisors is an integer number (20105475).

Almost surely, 2^166698009 is an apocalyptic number.

It is an amenable number.

166698009 is a deficient number, since it is larger than the sum of its proper divisors (74567691).

166698009 is a wasteful number, since it uses less digits than its factorization.

166698009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36904 (or 36901 counting only the distinct ones).

The product of its (nonzero) digits is 139968, while the sum is 45.

The square root of 166698009 is about 12911.1583136448. The cubic root of 166698009 is about 550.3557026884.

The spelling of 166698009 in words is "one hundred sixty-six million, six hundred ninety-eight thousand, nine".