prime!

Jesús Gallinal

About this app

prime!® 12 computes prime factorization of integers as large as you want.

Ratings and reviews

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 ☺

What's new

Usage and presentation improvements.