The online computer game “Is this prime?” tests a player’s knowledge of prime numbers—and just surpassed 2,999,999 attempts. Give it a whirl.

Prime numbers are a central topic of study in math. Despite being an object of fascination for millennia, there are still a lot of unsolved problems involving primes. Prime numbers are one of the ...

There's a new behemoth in the ongoing search for ever-larger prime numbers — and it's nearly 25 million digits long. A prime is a number that can be divided only by two whole numbers: itself and ...