BREAKING NEWS: Largest prime discovered

39,916,801 has just been discovered to be the largest prime number.

$11$ is a positive integer such that $11! + 1$ is prime; let $n = 11!$.

Now, $n+2$ is clearly a multiple of 2, $n+3$ is a multiple of 3 and so on up to $2n$. Applying a similar argument accounts for all the numbers between $2n$ and $3n$, (e.g., $2n + 5$ is clearly a multiple of 5), between $3n$ and $4n$ and - in general - between $an$ and $(a+1)n$.

Thus, $11! + 1 = 39,916,801$ is the largest prime number.

Colin

Colin is a Weymouth maths tutor, author of several Maths For Dummies books and A-level maths guides. He started Flying Colours Maths in 2008. He lives with an espresso pot and nothing to prove.

Share

7 comments on “BREAKING NEWS: Largest prime discovered

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Sign up for the Sum Comfort newsletter and get a free e-book of mathematical quotations.

No spam ever, obviously.

Where do you teach?

I teach in my home in Abbotsbury Road, Weymouth.

It's a 15-minute walk from Weymouth station, and it's on bus routes 3, 8 and X53. On-road parking is available nearby.

On twitter