665888566 has 32 divisors (see below), whose sum is σ = 1173407040. Its totient is φ = 277516800.

The previous prime is 665888557. The next prime is 665888579.

It is a happy number.

665888566 is nontrivially palindromic in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 665888566.

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, 71626 + ... + 80386.

It is an arithmetic number, because the mean of its divisors is an integer number (36668970).

Almost surely, 2^665888566 is an apocalyptic number.

665888566 is a deficient number, since it is larger than the sum of its proper divisors (507518474).

665888566 is a wasteful number, since it uses less digits than its factorization.

665888566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8920.

The product of its digits is 16588800, while the sum is 58.

The square root of 665888566 is about 25804.8167209147. The cubic root of 665888566 is about 873.2404656542.

The spelling of 665888566 in words is "six hundred sixty-five million, eight hundred eighty-eight thousand, five hundred sixty-six".