66566866566 has 32 divisors (see below), whose sum is σ = 133979774976. Its totient is φ = 22048208000.

The previous prime is 66566866559. The next prime is 66566866601.

66566866566 is nontrivially palindromic in base 10.

It is a super-2 number, since 2×66566866566² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 66566866497 and 66566866506.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1012126 + ... + 1075886.

It is an arithmetic number, because the mean of its divisors is an integer number (4186867968).

Almost surely, 2^66566866566 is an apocalyptic number.

66566866566 is an abundant number, since it is smaller than the sum of its proper divisors (67412908410).

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

66566866566 is a wasteful number, since it uses less digits than its factorization.

66566866566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64868.

The product of its digits is 335923200, while the sum is 66.

The spelling of 66566866566 in words is "sixty-six billion, five hundred sixty-six million, eight hundred sixty-six thousand, five hundred sixty-six".