Is 1000! really = infinity... Is that not mathematically impossible?
No, it is not impossible. It is very large number:
1,000!=4.02387260077093773543702433923 x 10^2567
You have a double negative and you have confused our guest answwrer.
Yes it is impossible.
It is a specific very large number. It is not infinity.
Sometimes calculators call numbers, that are too big to calculate, infinity. But they aren't really. :))
it is not infinite, as 1000! has a finite number of digits, making it finite. I used Wolfram Alpha to prove this.