First, we consider the 3 groups of comic books as individual items and find the number of ways to arrange these groups.
There are 3 groups, so there are 3! = 6 ways to arrange them.
Within each group, the comic books can be arranged in any order.
For the Spiderman group, there are 6! = 720 ways to arrange the 6 books.
For the Archie group, there are 5! = 120 ways to arrange the 5 books.
For the Garfield group, there are 4! = 24 ways to arrange the 4 books.
Therefore, the total number of arrangements is 6 * 720 * 120 * 24 = 12,441,600.
The answer is: 12,441,600
Below is a math problem. Provide a detailed, step-by-step solution.

### Problem:
Mr. Reader has a collection of 6 different Spiderman comic books, 5 different Archie comic books, and 4 different Garfield comic books. When stacking the comic books, all the Spiderman books are grouped together, all the Archie books are grouped together, and all the Garfield books are grouped together. How many different orders are possible to stack these 15 comic books in a pile with the covers facing up and all of them facing the same direction? Express your answer as a whole number.

### Answer:
