Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| * 608: | \[{21^{608}-1\over20}\] | 25 × 11 × 13 × 17 × 229 × 457 × 1217 × 2689 × 13681 × 31873 × 62897 × 76913 × 97241 × 136649 × 300673 × 609673 × 6629177 × 6857635489<10> × 12061389013<11> × 54921106624003<14> × 8871582886760161<16> × 987749814642143197<18> × 4370570172021545617284038736601<31> × 4510053597010461591911520110711387257<37> × 3794540985952206860593938878074866571399837<43> × 23848487863547010345502490786885124142687474898584806522660829719703516387834496528669303281915582974063071914651383779605728395494339050141709260545891458383245593352481703463533697<182> × [629733625052771823038612577125110747030174552579103798598329246966791459529943712714399120837166784021989023465764047098479782994339423866040389407196964787702124070553163044267835689379694397602175883699588096576373723383304738771827176812537826932528251741209852318114945579027049650287968080092543938557987901990049550876680544422041854489914474516716021803406358661998474521281<381>] |