Quote:
Originally Posted by FloatingPoint
Hello!
Can anyone point me in the right direction on how to check if a 1 billion digit long number is prime?
Just as an FYI, I haven't even taken calculus yet, so I hope it's not too complex, but if someone could point me in the right direction, I'd be grateful.
Thanks!

I am curious. Why do you think that not having taken calculus is relevant?
The question you ask has nothing to do with calculus.
The subject area here is algebra and number theory.
You also express hope that it is "not too complex". This implies that you believe that
calculus is
(1) A complex subject It
can be, but it isn't always. Any area of math can be simple
or it can be complex. You are confusing "elementary" with "complex". Elementary problems
in math can be very complicated. Very advanced mathematics can be quite simple.
(2) It also implies that you think you will better understand "complicated" mathematics after
you take calculus. I can assure you that this is not true.
Number theory and algebra can be studied totally independently from calculus.
BTW. Testing billion digit arbitrary numbers for primality is beyond the range of current
algorithms and computers. It is possible that with moderate effort one can show that a
billion digit number isn't prime, but such a demonstration requires luck.