Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 731: | \[2^{731}-1\] | 431 × 9719 × 131071 × 2099863 × 67872792749091946529<20> × 223192283824457474300157944531480362369858813007<48> × 646778401121199228094766201503567587391877257095639732429903642984700499452064755544318099585551714062125998479034557090110663089536817<135> |