R49081 is the natural number consisting of 49081 “1” digits in decimal base, or (10^49081 - 1)/9. This number has now been proven to be a prime number, using some number-crunching algorithm. Somebody else will have to ELI5 that algorithm.
You know how some things are red and some are not? There are probably multiple red things in the same room as you are right now. Most people can easily tell if something is red or not by simply looking at it.
But what about places we cannot see? Even though we have never been there, it is a save bet that there are red things in let's say New York. And if we wanted to make sure, we could book a flight and go check. But is there something red in every village in the world? My guess would be yes, but we do not know for sure and it will be hard to visit every place because there are so many.
At this point you might have explained some things, but if you have not lost them yet you could take this further.
There are places even further away than every village. We know that Mars is red because it is so big and people have sent a robot there to be absolutely sure. But what about other planets? It is hard to tell because planets can be very far away and red things can be very small. And going there is no option because even the fastest rocket would not get there any time soon.
What this post mentions is the equivalent of someone building a very precise telescope fixed at a very specific place very far away and they saw something red there. Here the analogy breaks because there are other more conceptual problems with building such a telescope. Otherwise, I am surprised how many similarities there are actually :)
Numberblocks that are rectangles are not prime.
My son knew of "primality" at 5 because of this.
My 4.5yo will have no chance, more interested in sharks, trains or even better shark trains!
> As of March 2022, the largest known prime number 282,589,933 − 1, the largest probable prime R8177207 and the largest elliptic curve primality prime R49081 are all repunits.
Original response:
Almost correct, but it's 2^49081-1, not (10^49081-1)/9. And there's no division by 9 at all.
const R49081 = BigInt('1'.repeat(49081));