is 2 1557623 - 1
has 468892 decimal digits
takes 0.070 GHz-days to do one PRP test
Last-known PrimeNet details:
Exponent is not assigned to anyone
0 primality tests remaining
ResidueStatus
L-L-unknown--unknown-
PRP-unknown--unknown-

 Trial FactoringP-1 FactoringCombined
LimitGHz-daysProbabilityB1B2GHz-daysProbabilityGHz-daysProbability
Actual26838.266669.1176 %20000000040200000000154.100018.5889 %192.366674.8583 %
Target2610.197265.5738 %65003000000.00151.0501 %0.198765.9353 %
Difference+7+38.0694+3.5439 %+199993500+40199700000+154.0985+17.5388%+192.1679+8.9231 %

Known prime factors (8 factors, 409.0 bits, 0.02625609% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
155762365420167825.96321
3 × 7
-372.883e-122.084e-73.954e-7
1557623102803119926.61533
3 × 11
2008-07-153115.781e-122.225e-73.954e-7
15576239021752416011239.715289600
26 × 52 × 181
2008-07-15641817.918e-84.558e-68.436e-6
15576237886395777686731549.486253154832
24 × 3 × 7 × 753437
2014-04-30167534376.828e-50.00270.0050
15576231313705923268696331856.86642170214592
26 × 11 × 5581 × 10733
2015-03-105581107330.00660.00040.0007
1557623181463368380998314572063.9765825009273136
24 × 3 × 1613 × 75235189
2017-06-201613752351892.27860.26560.4958
155762335586611400712804037772271.5921142337118825056
25 × 3 × 7 × 11 × 154536947893
2019-07-1932154536947893552.56545.311,018.5
1557623319199500890037999260492374.75710246365805141488
24 × 3 × 11 × 123377 × 157290223
2019-07-191233771572902234,842.40.56261.0366

247 Composite Factors:
P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2015-03-11alpertronManual testing500000150000001221856.8660.0848.711%
2021-03-11Seth_TrManual testing500000008550000000
skipped known factor: 65420167
skipped known factor: 102803119
skipped known factor: 902175241601
skipped known factor: 788639577768673
skipped known factor: 131370592326869633
skipped known factor: 18146336838099831457
skipped known factor: 31919950089003799926049
---22.636%
2021-03-28Seth_TrManual testing20000000040200000000
skipped known factor: 65420167
skipped known factor: 102803119
skipped known factor: 902175241601
skipped known factor: 788639577768673
skipped known factor: 131370592326869633
skipped known factor: 18146336838099831457
skipped known factor: 31919950089003799926049
---26.317%


Trial Factoring results:
575859606162636465666768
 BitsFactor
dateuseridcompidfromtofactorbits*digitsGHz-days
2008-07-15J FeitsmaManual testing??
26.615
9
2008-07-15J FeitsmaManual testing??
39.715
12
2014-04-30TJAOIManual testing??
49.486
15
2017-06-20TJAOIManual testing263264*
63.976
20
1.231
2022-11-17LordJuliusManual testing261267
skipped known factors(?)
2022-12-23LordJuliusManual testing267268


ECM factoring results:
Total ECM effort:82.703 GHz-days
Estimated T-Level:27.009
DigitsB1CompleteFacMiss
201100029.6540.000%
25500003.9701.887%
302500000.40266.914%
3510000000.03296.840%
4030000000.00299.789%


ECM Summary

B1B2factorcurvesGHz-days
5000050000001669.282
500005000000814.529
50000500000040.224
2500003968441910034.32
2500003973487710034.35


Lucas-Lehmer results:
No L-L results for M1557623


PRP results:
dateuseridcompidcofactorsres64
2017-09-28alpertronManual testing
102803119
131370592326869633
18146336838099831457
65420167
788639577768673
902175241601
E253384D4DC01C96
2017-10-18Oliver KruseThreadripper-PC
65420167
102803119
902175241601
788639577768673
131370592326869633
18146336838099831457
E253384D4DC01C96
2019-07-20oodairacom1
65420167
102803119
902175241601
788639577768673
131370592326869633
18146336838099831457
3558661140071280403777
31919950089003799926049
32E4FD6900793560
2019-07-21arnaudstm-11-010
65420167
102803119
902175241601
788639577768673
131370592326869633
18146336838099831457
3558661140071280403777
31919950089003799926049
32E4FD6900793560


CERT results:
No CERT results for M1557623


P-1 factor-bounds graph:
B1 = 200000000, B2 = 40200000000 (P-1 stage 2)
B1 = 50000000, B2 = 8550000000 (P-1 stage 2)
B1 = 200000000 (P-1 stage 1)
B1 = 50000000 (P-1 stage 1)
B1 = 500000, B2 = 15000000 (P-1 stage 2)
B1 = 500000 (P-1 stage 1)
100
101
102
103
104
105
106
107
108
109
100
101
102
103
104
105
106
107
108
109
1010
1011
1012
TF factor-bounds graph:
268
267
this exponent TF target: 61
TF double-checked to: 67
ECM T-Level=27.01 ~= 73-bit
250
260
270
280
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Last modified: 2024-03-13T02:15:48+00:00