66564612217 has 8 divisors (see below), whose sum is σ = 70114973760. Its totient is φ = 63018946800.

The previous prime is 66564612181. The next prime is 66564612229. The reversal of 66564612217 is 71221646566.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66564612217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66564612287) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 1144909 + ... + 1201642.

It is an arithmetic number, because the mean of its divisors is an integer number (8764371720).

Almost surely, 2^66564612217 is an apocalyptic number.

It is an amenable number.

66564612217 is a deficient number, since it is larger than the sum of its proper divisors (3550361543).

66564612217 is a wasteful number, since it uses less digits than its factorization.

66564612217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2348063.

The product of its digits is 725760, while the sum is 46.

The spelling of 66564612217 in words is "sixty-six billion, five hundred sixty-four million, six hundred twelve thousand, two hundred seventeen".