Base 21 Repunits
Table
Format: small prime × proven prime<size> × (probable prime)<size> × [composite]<size> × {unknown}<size>
| 312: | \[{21^{312}-1\over20}\] | 23 × 11 × 132 × 17 × 53 × 61 × 73 × 79 × 157 × 313 × 421 × 463 × 547 × 1171 × 1873 × 3181 × 6709 × 11701 × 32969 × 97241 × 101089 × 189437 × 629773 × 516094151 × 518118697 × 7021471715414521<16> × 23509884574335185209<20> × 7691526674487958994017<22> × 80459337199345300130638393<26> × 193538987428465501811153413<27> × 14394080037015419873205085261549<32> × 533920169777048201800962081353257<33> × 2927682077813715874149933185385605053168690918973651083914101281<64> × 27383949499163466212417038123409067260313051993309557922341284930956070895671507352615377<89> |