66804713217 has 12 divisors (see below), whose sum is σ = 105268033104. Its totient is φ = 40487704920.

The previous prime is 66804713207. The next prime is 66804713237. The reversal of 66804713217 is 71231740866.

66804713217 is a `hidden beast` number, since 66 + 80 + 471 + 32 + 17 = 666.

It is not a de Polignac number, because 66804713217 - 2¹⁰ = 66804712193 is a prime.

It is a super-2 number, since 2×66804713217² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66804713207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 337397443 + ... + 337397640.

It is an arithmetic number, because the mean of its divisors is an integer number (8772336092).

Almost surely, 2^66804713217 is an apocalyptic number.

It is an amenable number.

66804713217 is a deficient number, since it is larger than the sum of its proper divisors (38463319887).

66804713217 is a wasteful number, since it uses less digits than its factorization.

66804713217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 674795100 (or 674795097 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The spelling of 66804713217 in words is "sixty-six billion, eight hundred four million, seven hundred thirteen thousand, two hundred seventeen".