Hunting Giant Primes

The largest known prime, found in 2024, has over 41 million digits. No lab found it — the Great Internet Mersenne Prime Search (GIMPS) did, a long-running volunteer project. For 28 years its record-holders came from ordinary home PCs grinding through candidates in the background, but the 2024 giant broke that streak: it was the first cracked on a network of thousands of cloud datacenter GPUs.

These giants are all Mersenne primes, written as 2^p − 1. They are easy for computers to test, which is why the record-holders almost always take this form. Despite centuries of effort, only 52 are known.