There is a new "largest known prime number". More links & stuff in full description below ↓↓↓ Extra footage: https://www.youtube.com/watch?v=o0ZOs7sMS7k More on Mersenne Primes: https://www.youtube.com/watch?v=PLL0mo5rHhk Perfect Numbers: https://www.youtube.com/watch?v=ZfKTD5lvToE Googolplex: https://www.youtube.com/watch?v=8GEebx72-qs Graham's Number: https://www.youtube.com/watch?v=XTeJ64KD5cg This video features Dr Tony Padilla from the University of Nottingham. NUMBERPHILE Website: http://www.numberphile.com/ Numberphile on Facebook: http://www.facebook.com/numberphile Numberphile tweets: https://twitter.com/numberphile Subscribe: http://bit.ly/Numberphile_Sub Videos by Brady Haran Patreon: http://www.patreon.com/numberphile Brady's videos subreddit: http://www.reddit.com/r/BradyHaran/ Brady's latest videos across all channels: http://www.bradyharanblog.com/ Sign up for (occasional) emails: http://eepurl.com/YdjL9 Numberphile T-Shirts: null Other merchandise: https://store.dftba.com/collections/numberphile