66686220866 has 8 divisors (see below), whose sum is σ = 100110725820. Its totient is φ = 33315978928.

The previous prime is 66686220859. The next prime is 66686220883. The reversal of 66686220866 is 66802268666.

It can be written as a sum of positive squares in 2 ways, for example, as 66604770241 + 81450625 = 258079^2 + 9025^2 .

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

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, 13562681 + ... + 13567596.

Almost surely, 2^66686220866 is an apocalyptic number.

66686220866 is a deficient number, since it is larger than the sum of its proper divisors (33424504954).

66686220866 is a wasteful number, since it uses less digits than its factorization.

66686220866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27131508.

The product of its (nonzero) digits is 11943936, while the sum is 56.

The spelling of 66686220866 in words is "sixty-six billion, six hundred eighty-six million, two hundred twenty thousand, eight hundred sixty-six".