66556265566 has 24 divisors (see below), whose sum is σ = 117867245256. Its totient is φ = 28098378000.

The previous prime is 66556265551. The next prime is 66556265609.

It is a happy number.

66556265566 is nontrivially palindromic in base 10.

66556265566 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a self number, because there is not a number n which added to its sum of digits gives 66556265566.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5061685 + ... + 5074816.

It is an arithmetic number, because the mean of its divisors is an integer number (4911135219).

Almost surely, 2^66556265566 is an apocalyptic number.

66556265566 is a deficient number, since it is larger than the sum of its proper divisors (51310979690).

66556265566 is a wasteful number, since it uses less digits than its factorization.

66556265566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10136584 (or 10136577 counting only the distinct ones).

The product of its digits is 58320000, while the sum is 58.

The spelling of 66556265566 in words is "sixty-six billion, five hundred fifty-six million, two hundred sixty-five thousand, five hundred sixty-six".