Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
551: | \[2^{551}-1\] | 233 × 1103 × 2089 × 4409 × 14327 × 27551 × 524287 × 15047207907283785223567857264566942009057638990573141456392568106577256738933540911210280244101118007417805328040232877487303293567630046047<140> |