# Here’s an easy and fun way to memorize the world’s longest prime number

As you may remember, the largest known prime number, M82589933 (or 2^{82,589,933}-1), was discovered earlier this month. At over 24.8 million digits, it’s a long-ish number, but of course this doesn’t mean you shouldn’t be able to memorize it. In fact, as Evelyn Lamb explains in Scientific American, it isn’t even that hard.

Well, it’s a little hard. But it’s nothing compared to the effort of memorizing *over 24 million digits,* which is just too many digits for anyone to think about. Plus, it’s an excellent party trick for New Year’s parties—you can use it as a countdown, instead of the trite ten-second-to-midnight-routines. People will think you are a genius! Which, who’s to say you aren’t?

So Lamb (who is clearly more likely than others to be a genius) starts her memorization trick by turning M82589933 into a binary number. 2^{82,589,933}-1, in binary, is a string of the number 1 repeated 82,589,933 times.

82,589,933 is easy enough to remember. To make it easier, Lamb suggests you memorize the sentence: “Cabbages in April besmirch September asparagus. And how!” The number of letters in each word corresponds to a digit of 82,589,933.

Because not everyone is an actual genius, it might take you a minute to figure out what this actually means—just as it did my friend, who, of course, is me.

So here is a handy guide:

cabbages = eight letters = 8

in = two letters = 2

April = five letters = 5

besmirch = eight letters = 9

September = nine letters = 9

asparagus = nine letters = 9

and = three letters = 3

how = three letters = 3

That is: **82,599,933**.

Now, how do you keep track of how many ones have you written? Easy, says Lamb. Just memorize a series of words that are made of straight lines, like the word TWENTY NINE, which is made of 29 straight traits.

That is:

T= two straight lines = 11

W = four straight lines = 1111

E = four straight lines = 1111

N = three straight lines = 111

T = two straight lines = 11

Y = three straight lines = 111

N = three straight lines = 111

I = one straight line = 1

N = three straight lines = 111

E = four straight lines = 1111

TWENTY NINE = 11 1111 1111 111 11 111 111 1 111 1111 (that is 1 repeated 29 times. Probably.)

Lamb created a poem that, when written in all caps, contains 500 straight lines. But you don’t need her poem: You can write your own 500-straight-lines poem! You can even write a poem with another number of straight lines—for instance, 677. You can write a poem made of 677 straight lines 122008 times, and then write 1 just 517 more times!

You can start now and say it out loud and when you’re done it will be the next year!

Happy 2019! (That is 11111100011, in binary. Thank you for asking.)