Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 554: | \[2^{554}-1\] | 3 × 1121297 × 25792643401363<14> × 31133636305610209482201109050392404721<38> × 6955979459776540052280934851589652278783<40> × 3138280009399679017344631051542622769205877134953845128202334345822857<70> |