PrimeGrid is a distributed computing project for searching for prime numbers of world-record size. It makes use of the Berkeley Open Infrastructure for Network Computing (BOINC) platform. As of October 2020, there are about 3,300 active participants (on about 16,000 host computers) from 89 countries, reporting about 1,860 teraflops.
- PrimeGrid 321 Prime Search searching for mega primes of the form 3•2n±1.
- PrimeGrid AP27 Search: searching for an arithmetic progression (p+dn) that yields primes for 27 consecutive values of n.
- PrimeGrid Cullen Prime Search / PrimeGrid Woodall Prime Search: searching for mega primes of the forms n•2n±1.
- PrimeGrid Extended Sierpiński Project: helping solve the Extended Sierpiński Problem.
- PrimeGrid Fermat Divisor Search: searching for large prime divisors of Fermat numbers.
- PrimeGrid Generalized Cullen Prime Search: searching for primes of the form n•bn+1.
- PrimeGrid Generalized Fermat Prime Search: searching for megaprimes of the form b2n+1.
- Prime Sierpiński problem: helping Prime Sierpiński Project solve the Prime Sierpiński problem.
- PrimeGrid Proth Prime search: searching for primes of the form k•2n+1.
- PrimeGrid Seventeen or Bust: helping to solve the Sierpiński problem.
- PrimeGrid Sierpiński base 5 / PrimeGrid Riesel base 5: helping to solve the Sierpiński-Riesel Base 5 Problem.
- PrimeGrid Sophie Germain Search: searching for primes p and 2p+1, and twin primes p and p+2.
- PrimeGrid Riesel Problem: helping to solve the Riesel problem.