66564173388400 has 120 divisors (see below), whose sum is σ = 166693984833200. Its totient is φ = 25519398727680.

The previous prime is 66564173388389. The next prime is 66564173388443. The reversal of 66564173388400 is 488337146566.

66564173388400 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 pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 32572425 + ... + 34555624.

Almost surely, 2^{66564173388400} is an apocalyptic number.

It is an amenable number.

66564173388400 is an abundant number, since it is smaller than the sum of its proper divisors (100129811444800).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66564173388400 is a wasteful number, since it uses less digits than its factorization.

66564173388400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 67128171 (or 67128160 counting only the distinct ones).

The product of its (nonzero) digits is 69672960, while the sum is 61.

The spelling of 66564173388400 in words is "sixty-six trillion, five hundred sixty-four billion, one hundred seventy-three million, three hundred eighty-eight thousand, four hundred".