Largest known repunit prime

The largest known  is equal to R1,031 = (101,031 − 1) / 9 which is 1,031 digits long; it has been discovered in December 1985.

The largest known repunit probable prime is equal to R270,343 = (10270,343 − 1) / 9 which is 270,343 digits long; it has been discovered on July 11, 2007.