is 2 55621 - 1
has 16744 decimal digits
takes 0.000 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
Actual267534.221276.1194 %63000000082076369316942076,908.862430.8984 %77,443.083683.4981 %
Target2440.000063.6364 %500500000.00002.1031 %0.000064.4011 %
Difference+23+534.2212+12.4830 %+629999500+820763693119420+76,908.8624+28.7953%+77,443.0836+19.0970 %

Known prime factors (3 factors, 184.5 bits, 0.33173378% known):
Remaining cofactor is not a probable-prime

P-1GHz-days
exponentfactordigitsbits*kdate foundmin B1min B2min. TFmin. P-1normal P-1
5562142271961825.333380
22 × 5 × 19
-5198.037e-119.911e-91.750e-8
5562114191193087959191650.33412757045979
23 × 554654173
2009-06-20235546541730.00270.05200.0971
5562158353904755972403267595019146674333108.8475245672026390428369464322751
34 × 13 × 367 × 13573964167230589051301
2016-06-27367135739641672305890513012.308e+121.272e+122.376e+12

4 Composite Factors:
P-1 results:
dateusercompB1B2BSstagefactordigitsbits*GHz-daysFac Prob
2016-09-29kkmrkkblmbrbkManual testing100000000200000000012
skipped known factor: 42271961
skipped known factor: 1419119308795919
---39.690%
2023-04-21JacobZGreatLakes630000000820763693169420
skipped known factor: 42271961
skipped known factor: 1419119308795919
--120,67771.044%


P+1 Factoring results:
dateuseridcompidb1b2startfactorSmoothdigitsbits*ghz-days
2021-05-02ATHcolab-Pp215000000150000000027--0.176
2021-11-14fbaurubuntu50000000400000000065--0.493


Trial Factoring results:
5758596061626364656667
No TF results for M55621


ECM factoring results:
Total ECM effort:112.837 GHz-days
Estimated T-Level:33.524
DigitsB1CompleteFacMiss
2011000204.8220.000%
255000039.4180.000%
302500005.8310.293%
3510000000.70549.419%
4030000000.07193.116%
45110000000.00699.385%


ECM Summary

B1B2factorcurvesGHz-days
10.002
5000050000002790.326
250000250000004682.896
250000250000001160.718
100000010000000060616.35
1950007458350086315060.23
282133774431907555032.31


Lucas-Lehmer results:
No L-L results for M55621


PRP results:
dateuseridcompidcofactorsres64
2017-09-21Oliver KrusePRP
42271961
1419119308795919
583539047559724032675950191466743
DC97454763338E06
2017-09-21Oliver KruseManual testing
42271961
1419119308795919
583539047559724032675950191466743
DC97454763338E06
2017-11-06kkmrkkblmbrbkc4.xlarge
42271961
1419119308795919
583539047559724032675950191466743
DC97454763338E06
2020-04-17Oliver KruseAddPrpType5
42271961
1419119308795919
583539047559724032675950191466743
7C06E9F5170FD77C
2024-02-03Wentao HuangManual testing
42271961
1419119308795919
583539047559724032675950191466743
7C06E9F5170FD77C


CERT results:
No CERT results for M55621


P-1 factor-bounds graph:
B1 = 630000000, B2 = 820763693169420 (P-1 stage 2)
B1 = 630000000 (P-1 stage 1)
B1 = 100000000, B2 = 2000000000 (P-1 stage 2)
B1 = 100000000 (P-1 stage 1)
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TF factor-bounds graph:
this exponent TF target: 44
TF double-checked to: 67
ECM T-Level=33.52 ~= 95-bit
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Last modified: 2024-02-09T03:30:02+00:00