66666605056 has 20 divisors (see below), whose sum is σ = 133203002922. Its totient is φ = 33333302272.

The previous prime is 66666605041. The next prime is 66666605063. The reversal of 66666605056 is 65050666666.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 47356723456 + 19309881600 = 217616^2 + 138960^2 .

It is a junction number, because it is equal to n+sod(n) for n = 66666604994 and 66666605012.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65103595 + ... + 65104618.

Almost surely, 2^66666605056 is an apocalyptic number.

It is an amenable number.

66666605056 is a deficient number, since it is larger than the sum of its proper divisors (66536397866).

66666605056 is an equidigital number, since it uses as much as digits as its factorization.

66666605056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 130208231 (or 130208215 counting only the distinct ones).

The product of its (nonzero) digits is 6998400, while the sum is 52.

The spelling of 66666605056 in words is "sixty-six billion, six hundred sixty-six million, six hundred five thousand, fifty-six".