66681346808 has 16 divisors (see below), whose sum is σ = 125052893280. Its totient is φ = 33333908608.

The previous prime is 66681346729. The next prime is 66681346817. The reversal of 66681346808 is 80864318666.

It is a happy number.

66681346808 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

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, 803585 + ... + 882672.

It is an arithmetic number, because the mean of its divisors is an integer number (7815805830).

Almost surely, 2^66681346808 is an apocalyptic number.

It is an amenable number.

66681346808 is a deficient number, since it is larger than the sum of its proper divisors (58371546472).

66681346808 is a wasteful number, since it uses less digits than its factorization.

66681346808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1691206 (or 1691202 counting only the distinct ones).

The product of its (nonzero) digits is 7962624, while the sum is 56.

The spelling of 66681346808 in words is "sixty-six billion, six hundred eighty-one million, three hundred forty-six thousand, eight hundred eight".