| 2257877 | Composite, with 2 known prime factors. Cofactor is composite. Trial Factored to 268 TF target 262 |
| Factored | |
| ECM | | Digits | B1 | Curves |
|---|
| 25 | 50000 | 280 / 280 | | 30 | 250000 | 156 / 640 |
Estimated T-Level: 26.2 ⓘ TF below 2^82 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 |
|---|
| Factored | PRP without proof (not generated) | 2017-10-10 | Oliver Kruse | 28F1BA3C26293AC7 | 1 | 0 | 1 | 3 | | Factored | PRP without proof (not generated) | 2017-11-21 | storm5510 | 28F1BA3C26293AC7 | 1 | 1639351 | 1 | 3 | | Verified | Certified Good | 2025-10-26 | blin00 | 63A6029F83026C6E | 2 | 1159356 | 5 | 3 |
|
| History | | Date | User | Type | Result |
|---|
| 2025-10-26 | Choi4KANG | CERT | Proof certified good | | 2025-10-26 | blin00 | C-PRP | M2257877/2235298231/227920839993876197446391 : 63A6029F83026C6E Proof Certified Good
Proof Power: 7
| | 2025-10-21 | TJAOI | F-ECM | Factor: 227920839993876197446391 / ECM curve 20, B1=250000, B2=251325195, Edwards Sigma=5678908898725110 | | 2017-11-21 | storm5510 | C-PRP | M2257877/2235298231 : 28F1BA3C26293AC7 | | 2017-10-10 | Oliver Kruse | C-PRP | M2257877/2235298231 : 28F1BA3C26293AC7 | | 2016-04-13 | alpertron | NF-PM1 | B1=500000, B2=15000000, E=12 |
|
