Prime Factors Calculator for Very Big Numbers
 
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This calculator will calculate the prime factors of a positive integer. The algorithm used can, in theory, handle very large numbers but beware that numbers with large prime factors could take a long time to factorise. For example, 1234567890123456789012345678901234567890 factorises almost instantly, whereas 12345678901234567 takes a lot longer, because, even though smaller, one of the prime factors is a large number. The old Java Applet version of this page is available here but I'm not maintaining it. This one is probably now faster. Number to factorise:

 
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Whilst I try to keep the information on this site accurate, I'm only human and I do occasionally make mistakes.
I therefore advise you to check any information before using it for anything important. If you do find any errors, please let me know so that I can correct them.
Click here to report an error on this page. This page was last changed on: 09 July 2022. Thanks for visiting my site. 