Sophie Germain prime
Primegrid worked with the Twin Prime Search to search for a record-sized twin prime at approximately 58,700 digits. The new world's largest known twin prime was eventually discovered on January 15, 2007 (sieved by Twin Prime Search and tested by PrimeGrid). The search continued for another record twin prime at just above 100,000 digits. It was completed in August 2009 when Primegrid found . Continued testing for twin primes in conjunction with the search for a Sophie Germain prime yielded a new record twin prime on September 2016 upon finding the number composed of 388,342 digits.