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.

## TeaKayB

@icecolbeveridge OH MY GOD THAT’S AMA- wait a minute…

## TeaKayB

RT @icecolbeveridge: [FCM] BREAKING NEWS: Largest prime discovered: http://t.co/QqFnxxZp2S cc @aperiodical

## C_J_Smith

RT @icecolbeveridge: [FCM] BREAKING NEWS: Largest prime discovered: http://t.co/QqFnxxZp2S cc @aperiodical

Pingback: The Aperiodical | Largest prime discovered

## SherriBurroughs

Think I’ll start class with this one MT @icecolbeveridge: [FCM] BRKNG NEWS: Largest prime discovered: http://t.co/VUgjRhOzmo cc @aperiodical

## DeathEndsFun

Eat your heart out Euclid! 39,916,801 is the largest prime! http://t.co/dwrn0is7VK

## rajeshja

Now if only it weren’t April 1. RT @DeathEndsFun: Eat your heart out Euclid! 39,916,801 is the largest prime! http://t.co/Lu9D3RpWUp