Base 5 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 261: | \[{5^{261}-1\over4}\] | 19 × 31 × 59 × 829 × 5569 × 6961 × 35671 × 6717619 × 81131329 × 22125996444329<14> × 420610743056505018221215111<27> × 28870194250662203210437116612769<32> × 11566136229005308986654971792863317115138766959390489944515828805834193517341<77> |