The largest prime number ever looks like this: 277,232,917 − 1.
It is called M77232917. It is 23,249,425 digits long! Hmmm… how long is that? According to mathematicians, writing it out would take 54 days straight, and the number would cover 73 miles!
What does this number mean? This means that if you took the number 2 and multiplied it 77,232,917 times with itself (2x2x2x2x2x2 and so on, 77,232,917 times) and then took 1 away from the resulting number, you would have the largest prime number ever.
It was found by a man called John Pace, in Tennessee, USA, using a lot of computing power. It was part of something called the Great Internet Mersenne Prime Search, a search for prime numbers. It is named after Marin Mersenne, the scientist who enjoyed studying prime numbers.
Why was John Pace looking for a large prime number? There was a $100,000 prize announced for the first person who discovered a prime number more than 10 million digits long. John Pace rolled up his sleeves, dusted off his computer, and in his spare time, worked hard at figuring out what this number could be. It took him 14 years! The last large prime number was found 2 years ago, and was 22 million digits long. Will John Pace get a prize? Let’s wait and see!
What is a prime number? It is a number that is divisible only by 1 and by itself. For example… 2, 3, 5, 7, 11, 13, 17, 19 are the prime numbers between 1 and 20. 9 wouldn’t be, for example, because it is divisible by 1, 3, and 9.
Why should we care about the largest prime number ever? These complex numbers are used in computer coding and are used for applications such as cryptography. Using secret codes to protect information from people such as hackers.