668528686825866 has 48 divisors (see below), whose sum is σ = 1449096293467368. Its totient is φ = 222747919152000.

The previous prime is 668528686825859. The next prime is 668528686825871.

668528686825866 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in 4 ways, for example, as 525420605423025 + 143108081402841 = 22922055^2 + 11962779^2 .

It is a super-3 number, since 3×668528686825866³ (a number of 45 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 418817980 + ... + 420411176.

Almost surely, 2^{668528686825866} is an apocalyptic number.

668528686825866 is an abundant number, since it is smaller than the sum of its proper divisors (780567606641502).

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

668528686825866 is a wasteful number, since it uses less digits than its factorization.

668528686825866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1603127 (or 1603124 counting only the distinct ones).

The product of its digits is 152882380800, while the sum is 90.

The spelling of 668528686825866 in words is "six hundred sixty-eight trillion, five hundred twenty-eight billion, six hundred eighty-six million, eight hundred twenty-five thousand, eight hundred sixty-six".