66404166566 has 8 divisors (see below), whose sum is σ = 99683051160. Its totient is φ = 33176482848.

The previous prime is 66404166557. The next prime is 66404166583. The reversal of 66404166566 is 66566140466.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12796976 + ... + 12802163.

It is an arithmetic number, because the mean of its divisors is an integer number (12460381395).

Almost surely, 2^66404166566 is an apocalyptic number.

66404166566 is a deficient number, since it is larger than the sum of its proper divisors (33278884594).

66404166566 is a wasteful number, since it uses less digits than its factorization.

66404166566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25600438.

The product of its (nonzero) digits is 3732480, while the sum is 50.

The spelling of 66404166566 in words is "sixty-six billion, four hundred four million, one hundred sixty-six thousand, five hundred sixty-six".