Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 412: | \[{21^{412}-1\over20}\] | 22 × 11 × 13 × 17 × 2473 × 4327 × 7211 × 49853 × 2560169 × 17486925079333<14> × 57396107489297<14> × 573079972724225525536065884172119<33> × 124182167703174868733039024056091426756491656943<48> × 1367397284535016101800205204505932360525244596116383<52> × 3578319942163234761948197423711625937273928656180280573469957211934243130134304207939291415435034091514822796033427258153670673<127> × [84852336440799242880166023623577839053361133393910537075544139009058326035007965276327630712108188255473156910309098615778264077993118537083085580114966928880568640583641353416894358505304736208967608470697317769429137440843747179093<233>] |