A number with 41 million digits: the new largest prime

For six years the record sat untouched. Then, in October 2024, the Great Internet Mersenne Prime Search announced a new largest known prime number, written as 2 to the power of 136,279,841, minus 1. Spelled out, it has 41,024,320 digits. That's about 16 million more digits than the previous record holder.

What kind of number is that?

It's a Mersenne prime, which means it's one less than a power of two. They're rare. This is only the 52nd one ever found. The search runs on volunteers' computers all over the world, and this one was found using a network of graphics cards, the same kind of hardware that runs video games and AI.

Why bother?

Fair question for a 41-million-digit number nobody will ever use directly. A few honest reasons:

• It stress-tests hardware and algorithms. The math behind the search has led to real improvements in how computers multiply gigantic numbers.
• Primes are the backbone of encryption. Not these giant ones specifically, but the whole field of prime research keeps the math that secures the internet healthy.
• Curiosity counts. People have hunted primes since Euclid proved there are infinitely many of them, around 300 BC. We just have faster tools now.

For a high-school student, here's the nice takeaway. The prime numbers you meet in Grade 11, the same ones that feel like dusty definitions, are the front edge of a problem people are still actively working on, with hardware from this decade. Math isn't finished. Not even close.