665627726566 has 16 divisors (see below), whose sum is σ = 1107670178880. Its totient is φ = 297429954280.

The previous prime is 665627726531. The next prime is 665627726573.

665627726566 is nontrivially palindromic in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 665627726498 and 665627726507.

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, 256403836 + ... + 256406431.

It is an arithmetic number, because the mean of its divisors is an integer number (69229386180).

Almost surely, 2^665627726566 is an apocalyptic number.

665627726566 is a deficient number, since it is larger than the sum of its proper divisors (442042452314).

665627726566 is a wasteful number, since it uses less digits than its factorization.

665627726566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 512810339.

The product of its digits is 228614400, while the sum is 64.

The spelling of 665627726566 in words is "six hundred sixty-five billion, six hundred twenty-seven million, seven hundred twenty-six thousand, five hundred sixty-six".