668109186 has 24 divisors (see below), whose sum is σ = 1482878124. Its totient is φ = 217271040.

The previous prime is 668109181. The next prime is 668109203. The reversal of 668109186 is 681901866.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 667964025 + 145161 = 25845^2 + 381^2 .

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (668109181) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 451911 + ... + 453386.

Almost surely, 2^668109186 is an apocalyptic number.

668109186 is an abundant number, since it is smaller than the sum of its proper divisors (814768938).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

668109186 is a wasteful number, since it uses less digits than its factorization.

668109186 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 905346 (or 905343 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The square root of 668109186 is about 25847.8081469203. The cubic root of 668109186 is about 874.2100891865.

The spelling of 668109186 in words is "six hundred sixty-eight million, one hundred nine thousand, one hundred eighty-six".