666628826666 has 12 divisors (see below), whose sum is σ = 1099111165026. Its totient is φ = 303013102920.

The previous prime is 666628826641. The next prime is 666628826711.

666628826666 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in only one way, i.e., 480325233025 + 186303593641 = 693055^2 + 431629^2 .

It is a junction number, because it is equal to n+sod(n) for n = 666628826596 and 666628826605.

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 5 ways as a sum of consecutive naturals, for example, 1377332045 + ... + 1377332528.

Almost surely, 2^666628826666 is an apocalyptic number.

666628826666 is a deficient number, since it is larger than the sum of its proper divisors (432482338360).

666628826666 is a wasteful number, since it uses less digits than its factorization.

666628826666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2754664597 (or 2754664586 counting only the distinct ones).

The product of its digits is 429981696, while the sum is 68.

The spelling of 666628826666 in words is "six hundred sixty-six billion, six hundred twenty-eight million, eight hundred twenty-six thousand, six hundred sixty-six".