665565566 has 8 divisors (see below), whose sum is σ = 998571024. Its totient is φ = 332708560.

The previous prime is 665565557. The next prime is 665565581.

It is a happy number.

665565566 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25130 + ... + 44301.

It is an arithmetic number, because the mean of its divisors is an integer number (124821378).

Almost surely, 2^665565566 is an apocalyptic number.

665565566 is a deficient number, since it is larger than the sum of its proper divisors (333005458).

665565566 is a wasteful number, since it uses less digits than its factorization.

665565566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74226.

The product of its digits is 4860000, while the sum is 50.

The square root of 665565566 is about 25798.5574402911. The cubic root of 665565566 is about 873.0992496898.

The spelling of 665565566 in words is "six hundred sixty-five million, five hundred sixty-five thousand, five hundred sixty-six".