66688822778806 has 16 divisors (see below), whose sum is σ = 101239241495040. Its totient is φ = 32944587822720.

The previous prime is 66688822778779. The next prime is 66688822778827. The reversal of 66688822778806 is 60887722888666.

It is a self number, because there is not a number n which added to its sum of digits gives 66688822778806.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 544657501 + ... + 544779928.

It is an arithmetic number, because the mean of its divisors is an integer number (6327452593440).

Almost surely, 2^{66688822778806} is an apocalyptic number.

66688822778806 is a deficient number, since it is larger than the sum of its proper divisors (34550418716234).

66688822778806 is a wasteful number, since it uses less digits than its factorization.

66688822778806 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1089437799.

The product of its (nonzero) digits is 8323596288, while the sum is 82.

The spelling of 66688822778806 in words is "sixty-six trillion, six hundred eighty-eight billion, eight hundred twenty-two million, seven hundred seventy-eight thousand, eight hundred six".