665635536566 has 48 divisors (see below), whose sum is σ = 1347946541568. Its totient is φ = 239389394400.

The previous prime is 665635536563. The next prime is 665635536589.

665635536566 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 665635536499 and 665635536508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665635536563) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12761870 + ... + 12813921.

It is an arithmetic number, because the mean of its divisors is an integer number (28082219616).

Almost surely, 2^665635536566 is an apocalyptic number.

665635536566 is an abundant number, since it is smaller than the sum of its proper divisors (682311005002).

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

665635536566 is a wasteful number, since it uses less digits than its factorization.

665635536566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25575837 (or 25575824 counting only the distinct ones).

The product of its digits is 262440000, while the sum is 62.

The spelling of 665635536566 in words is "six hundred sixty-five billion, six hundred thirty-five million, five hundred thirty-six thousand, five hundred sixty-six".