Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 275: | \[2^{275}-1\] | 23 × 31 × 89 × 601 × 881 × 1801 × 3191 × 201961 × 382027665134363932751<21> × 4074891477354886815033308087379995347151<40> |