Contribution and Reservation

(32·10¹⁹⁶+13)/9 =: 3(5)₁₉₅7_<197>; = 37 · 25875341 · [37138098429735127392561163192437191879363482048834098880511795417921679214235706534687251501766139466952762514741775227656360585198122063819795107664898443694363717214817032206878392866821_<188>] SUBMIT/RESERVE

Status

Expression:	(32·10¹⁹⁶+13)/9
Composite Factor:	371380984297351273925611631924371918793634820488340988805117 954179216792142357065346872515017661394669527625147417752276 563605851981220638197951076648984436943637172148170322068783 92866821 (188-digit)
Status:	Not factored. Not reserved. You can submit its factors or reserve it for submitting in the future.

How to factor it

ECM, P-1, P+1

Look for prime factors by GMP-ECM first. Refer to the section "Efforts by ECM". Not only ECM but also P-1/P+1 may be helpful.

SNFS

Use GGNFS and/or Msieve if GMP-ECM cannot find a factor. The SNFS difficulty of this composite number is 197.51-digit and the GNFS difficulty is 187.57-digit. SNFS must be faster than GNFS. It will take about 16 CPU-days to factor this composite number on 64-bit Opteron-2600MHz.

Put factMsieve.pl to which $GGNFS_BIN_PATH and $NUM_CPUS were modified properly in the working directory 35557_196.
Put the following polynomial file 35557_196.poly in there too.
And then, run "perl factMsieve.pl 35557_196".

35557_196.poly ^*1

n: 37138098429735127392561163192437191879363482048834098880511795417921679214235706534687251501766139466952762514741775227656360585198122063819795107664898443694363717214817032206878392866821
m: 2000000000000000000000000000000000000000
deg: 5
c5: 10
c0: 13
skew: 1.05
type: snfs
lss: 1
rlim: 13700000
alim: 13700000
lpbr: 28
lpba: 28
mfbr: 55
mfba: 55
rlambda: 2.5
alambda: 2.5

*1 These parameters were not fully adjusted. The approximate expressions which were used for making the parameters are: deg=expt<=105?4:expt<=210?5:6 or expt<=144?4:6; d=log10(c[deg])+deg*log10(m)[digits]; time=10^(d/30-4)[hours]; skew=|c0/c[deg]|^(1/deg); rlim=round(7*10^(d/60+3)); lpbr=floor(d/25+21); mfbr=floor(d/8+31); rlambda=floor(d/25+18)/10;

Efforts by ECM

The efforts by ECM to find small factors of this 188-digit composite number so far are as follows. According to the reports, unknown prime factors of this composite number are probably 35-digit or more. Please report your efforts by ECM. (Anonymous reports are not acceptable)

Level	B1	Reported runs Total / Required runs (Required runs for lower level)	Name
35	1e6	0 / 0
40	3e6	300	Serge Batalov	Nov 27, 2008
		300 / 2336
		/ 2036
45	11e6	0 / 4413 (590)
45	11e6	/ 4413 (590)
50	43e6	0 / 7542 (1258)
50	43e6	/ 7542 (1258)
55	11e7	0 / 17767 (3129)
55	11e7	/ 17767 (3129)

Command line to find prime factors up to about 40-digit

echo 37138098429735127392561163192437191879363482048834098880511795417921679214235706534687251501766139466952762514741775227656360585198122063819795107664898443694363717214817032206878392866821 | ecm -n -c 2036 3e6

Command line to find prime factors up to about 45-digit

echo 37138098429735127392561163192437191879363482048834098880511795417921679214235706534687251501766139466952762514741775227656360585198122063819795107664898443694363717214817032206878392866821 | ecm -n -c 4413 11e6

Command line to find prime factors up to about 50-digit

echo 37138098429735127392561163192437191879363482048834098880511795417921679214235706534687251501766139466952762514741775227656360585198122063819795107664898443694363717214817032206878392866821 | ecm -n -c 7542 43e6

Command line to find prime factors up to about 55-digit

echo 37138098429735127392561163192437191879363482048834098880511795417921679214235706534687251501766139466952762514741775227656360585198122063819795107664898443694363717214817032206878392866821 | ecm -n -c 17767 11e7

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