665603306566 has 16 divisors (see below), whose sum is σ = 1094642265600. Its totient is φ = 301026619080.

The previous prime is 665603306551. The next prime is 665603306573.

665603306566 is nontrivially palindromic in base 10.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76012446 + ... + 76021201.

It is an arithmetic number, because the mean of its divisors is an integer number (68415141600).

Almost surely, 2^665603306566 is an apocalyptic number.

665603306566 is a deficient number, since it is larger than the sum of its proper divisors (429038959034).

665603306566 is a wasteful number, since it uses less digits than its factorization.

665603306566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152033859.

The product of its (nonzero) digits is 10497600, while the sum is 52.

The spelling of 665603306566 in words is "six hundred sixty-five billion, six hundred three million, three hundred six thousand, five hundred sixty-six".