Base 2 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 641: | \[2^{641}-1\] | 35897 × 49999 × 1173835097 × 2401258891949526685926151441<28> × 745276300734440606226386924312213175677903182797334854064486587296999<69> × 2420161564200739329410254310444778820196576654139080232429544162649795567983079<79> |