665656568 has 16 divisors (see below), whose sum is σ = 1248407160. Its totient is φ = 332748000.

The previous prime is 665656567. The next prime is 665656577. The reversal of 665656568 is 865656566.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665656567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39698 + ... + 53918.

Almost surely, 2^665656568 is an apocalyptic number.

It is an amenable number.

665656568 is a deficient number, since it is larger than the sum of its proper divisors (582750592).

665656568 is a wasteful number, since it uses less digits than its factorization.

665656568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20078 (or 20074 counting only the distinct ones).

The product of its digits is 7776000, while the sum is 53.

The square root of 665656568 is about 25800.3210832734. The cubic root of 665656568 is about 873.1390404888.

The spelling of 665656568 in words is "six hundred sixty-five million, six hundred fifty-six thousand, five hundred sixty-eight".