Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 267: | \[2^{267}-1\] | 7 × 78903841 × 28753302853087<14> × 618970019642690137449562111<27> × 24124332437713924084267316537353<32> |