is 2 1891861 - 1
has 569507 decimal digits
takes 0.103 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
-unknown- primality tests remaining
ResidueStatus
L-L-unknown--unknown-
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbabilityProb over default TF
Actual26715.706268.6567%5001005001000.03932.0050%15.745569.2851%0.6284%
PrimeNet2570.010163.1579%90001600000.00143.0356%0.011564.2763%1.1184%
GPU722610.162465.5738%100001600000.00141.7259%0.163866.1679%0.5942%
Difference+6+15.5438+3.0829%+490100+340100+0.0379+0.2791%+15.5817+3.1172%+3.1172%

Known prime factors (1 factor, 54.6 bits, 0.00288689% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
1891861276067526516445611754.6167296189480
23 × 33 × 5 × 857 × 7883
-85778830.00239.753e-50.0001

P-1 results:
 GHz-DaysworthFactor
probability
dateuseridcompidb1b2estagefactordigitsbits*spentsaved
2022-04-12T11:56:56Lisander ViaeneDesktop500100500100-
skipped known factor: 27606752651644561
--0.039--2.005%


Trial Factoring results:
No TF results for M1891861


ECM factoring results:

Old Calculation Method

Total ECM effort:19.258 GHz-days
Estimated T-Level:24.482
DigitsB1CurvesCompleteFacMiss
2011000251 / 1002.5108.025%
2550000251 / 2800.89640.737%

New Calculation Method

Total ECM effort:19.258 GHz-days
Estimated T-Level:24.482
DigitsB1CompleteFacMiss
201100010.3240.003%
25500000.95038.665%
302500000.06094.149%
3510000000.00399.717%


ECM Summary

B1B2factorcurvesGHz-days
500005000000422.912
50000660000020916.35


Lucas-Lehmer results:
No L-L results for M1891861


PRP results:
dateuseridcompidcofactorsres64PRP
2017-10-04T16:27:26Oliver KruseGTX-2
27606752651644561
1083A17021C851__no
2017-11-08T20:24:09kkmrkkblmbrbkold
27606752651644561
1083A17021C851__no


P-1 factor-bounds graph:
B1 = 500100 (P-1 stage 1)
101
102
103
104
105
106
101
102
103
104
105
106
TF factor-bounds graph:
267
250
260
270
280
290
2100
Last modified: 2022-04-12T11:56:56+00:00