After playing around with the scoring system in an emulator, I found that it doesn't exactly crash when it hits 8,388,600 points. It will crash the next time points are added to a score over 8,388,600. This normally doesn't make a huge difference since it will trigger as the bonus is counting up. However, there is an option to press start to add the rest of the bonus in one frame. So, say your bonus is 2 million and your current points are 8 million. You can press start to achieve 10 million to finish the level without crashing the game. However, the next time you get points, the game will crash.
Just to double check the rules, is the goal to get as close to 8,388,600 without tying or going over? Or is it to get the maximum score without crashing the game?