66550205566 has 16 divisors (see below), whose sum is σ = 108508894704. Its totient is φ = 30428417664.

The previous prime is 66550205563. The next prime is 66550205599.

66550205566 is nontrivially palindromic in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66550205563) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11958075 + ... + 11963638.

It is an arithmetic number, because the mean of its divisors is an integer number (6781805919).

Almost surely, 2^66550205566 is an apocalyptic number.

66550205566 is a deficient number, since it is larger than the sum of its proper divisors (41958689138).

66550205566 is a wasteful number, since it uses less digits than its factorization.

66550205566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23921835.

The product of its (nonzero) digits is 1620000, while the sum is 46.

The spelling of 66550205566 in words is "sixty-six billion, five hundred fifty million, two hundred five thousand, five hundred sixty-six".