166666686 has 8 divisors (see below), whose sum is σ = 333333384. Its totient is φ = 55555560.

The previous prime is 166666673. The next prime is 166666693. The reversal of 166666686 is 686666661.

It is a sphenic number, since it is the product of 3 distinct primes.

166666686 is an admirable number.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

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 in 3 ways as a sum of consecutive naturals, for example, 13888885 + ... + 13888896.

It is an arithmetic number, because the mean of its divisors is an integer number (41666673).

Almost surely, 2^166666686 is an apocalyptic number.

166666686 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

166666686 is a wasteful number, since it uses less digits than its factorization.

166666686 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27777786.

The product of its digits is 2239488, while the sum is 51.

The square root of 166666686 is about 12909.9452361348. The cubic root of 166666686 is about 550.3212294282.

The spelling of 166666686 in words is "one hundred sixty-six million, six hundred sixty-six thousand, six hundred eighty-six".