| 3581 | Composite, with 1 known prime factor. Cofactor is composite. Trial Factored to 268 TF target 244 |
| Factored | | Factor | Digits | Bits | Date |
|---|
| 21487 | 5 | 14.4 | old |
|
| ECM | | Digits | B1 | Curves |
|---|
| 25 | 50000 | 280 / 280 | | 30 | 250000 | 640 / 640 | | 35 | 1000000 | 1566 / 1566 | | 40 | 3000000 | 4588 / 4588 | | 45 | 11000000 | 9201 / 9201 | | 50 | 44000000 | 16550 / 16550 | | 55 | 110000000 | 11066 / 40830 |
Estimated T-Level: 51.4 ⓘ TF below 2^166 is very unlikely to find new factors due to ECM effort. |
| PRP Cofactor | | Status | Proof | Date | User | Residue | Number of
known factors | Shift | Type | Base |
|---|
| Verified | No proof (small exponent) | 2017-09-21 | Oliver Kruse | CDD31D1F4F8EEA80 | 1 | 0 | 1 | 3 | | Verified | No proof (small exponent) | 2017-10-12 | kkmrkkblmbrbk | CDD31D1F4F8EEA80 | 1 | 2525 | 1 | 3 | | Verified | No proof (small exponent) | 2020-04-17 | Oliver Kruse | AFB655A5E1BC9437 | 1 | 251 | 5 | 3 | | Verified | No proof (small exponent) | 2024-02-03 | Wentao Huang | AFB655A5E1BC9437 | 1 | 1979 | 5 | 3 |
|
| History | | Date | User | Type | Result |
|---|
| 2025-05-03 | masser | NF-PP1 | Start=127/43, B1=3100000000, B2=3096900000000 | | 2024-02-03 | Wentao Huang | C-PRP | M3581/21487 : AFB655A5E1BC9437 | | 2022-06-20 | mikr | NF-PM1 | B1=120000000000, B2=314605609292724750 | | 2021-09-05 | Jinyuan Wang | NF-PM1 | B1=1300000000, B2=13000000000 | | 2020-04-17 | Oliver Kruse | C-PRP | M3581/21487 : AFB655A5E1BC9437 | | 2017-10-12 | kkmrkkblmbrbk | C-PRP | M3581/21487 : CDD31D1F4F8EEA80 | | 2017-09-21 | Oliver Kruse | C-PRP | M3581/21487 : CDD31D1F4F8EEA80 | | 2017-09-21 | Oliver Kruse | C-PRP | M3581/21487 : CDD31D1F4F8EEA80 |
|
