66805866 has 24 divisors (see below), whose sum is σ = 144896544. Its totient is φ = 22245480.

The previous prime is 66805841. The next prime is 66805867. The reversal of 66805866 is 66850866.

66805866 is a `hidden beast` number, since 6 + 68 + 0 + 586 + 6 = 666.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66805867) 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, 31945 + ... + 33971.

It is an arithmetic number, because the mean of its divisors is an integer number (6037356).

Almost surely, 2^66805866 is an apocalyptic number.

66805866 is an abundant number, since it is smaller than the sum of its proper divisors (78090678).

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

66805866 is a wasteful number, since it uses less digits than its factorization.

66805866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3866 (or 3863 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The square root of 66805866 is about 8173.4855477942. The cubic root of 66805866 is about 405.7621496676.

The spelling of 66805866 in words is "sixty-six million, eight hundred five thousand, eight hundred sixty-six".