66566844866566 has 16 divisors (see below), whose sum is σ = 108957464970048. Its totient is φ = 30249351023400.

The previous prime is 66566844866539. The next prime is 66566844866611.

66566844866566 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×66566844866566² (a number of 28 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66566844866566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 415204740 + ... + 415365031.

It is an arithmetic number, because the mean of its divisors is an integer number (6809841560628).

Almost surely, 2^{66566844866566} is an apocalyptic number.

66566844866566 is a deficient number, since it is larger than the sum of its proper divisors (42390620103482).

66566844866566 is a wasteful number, since it uses less digits than its factorization.

66566844866566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 830573427.

The product of its digits is 42998169600, while the sum is 82.

The spelling of 66566844866566 in words is "sixty-six trillion, five hundred sixty-six billion, eight hundred forty-four million, eight hundred sixty-six thousand, five hundred sixty-six".