66655...22221 (54-digits)

This number is a prime.

                 6665 5554466335 5226600551 1444433332 2440000331 1110022221

Just showing those entries submitted by 'Rivera': (Click here to show all)

The largest prime obtained by laying down 27 valid domino pieces. Omitted piece 6-1. Found By G. Daddario. [Rivera]