prime!

Unbeatable. Close to the fast number factorisers you can find online in terms of speed (thinking of factordb or Number Empire, to be completely transparent), but I'm having a hard time understanding how the algorithm works. On the one hand probable primes less than 10^60 are confirmed prime almost immediately, even the 126-digit 1111...1109 took only about 2.5 seconds, but on the other hand the first time I tried the 34-digit 5777...7773 it wasn't able to factorise it? Seems unpredictable

This app is very fast, even for 100-digit numbers. It factors 2^346+1 almost instantly. It's the best app for finding prime factors. I would suggest omitting '1' from the prime factors of a number, since 1 is a unit, not a prime, but that's a very minor annoyance. Edit: I just realized that I accidentally gave this app only 1 star. Sorry! I meant 5 stars, and would give it 6 if I could.

I tried dozens, and this app rules. Massive numbers 50+ digits long factored in seconds. I checked results against other apps which took much longer time, and the results are the same. Awesome job ☺