Contribution and Reservation

(55·10¹⁸⁷+53)/9 =: 6(1)₁₈₆7_<188>; = 2016801382643310733_<19> · 91041909846726201221_<20> · 102340704059336916678649_<24> · [3252125446710873989110474588642423409501343730321563303887977916287900309667323820346751457434688345006866071847720899280739381_<127>] SUBMIT/RESERVE

Status

Expression:	(55·10¹⁸⁷+53)/9
Composite Factor:	325212544671087398911047458864242340950134373032156330388797 791628790030966732382034675145743468834500686607184772089928 0739381 (127-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.

GNFS

Use GGNFS and/or Msieve if GMP-ECM cannot find a factor. The SNFS difficulty of this composite number is 190.14-digit and the GNFS difficulty is 126.51-digit. GNFS must be faster than SNFS. It will take about 4 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 61117_187.
Put the following polynomial file 61117_187.poly in there too.
And then, run "perl factMsieve.pl 61117_187".

61117_187.poly ^*1

# Murphy_E = 1.296645e-10, selected by Jeff Gilchrist
n: 3252125446710873989110474588642423409501343730321563303887977916287900309667323820346751457434688345006866071847720899280739381
Y0: -2658722344792982229710329
Y1: 80094173771993
c0: -58643768912539716281445614361600
c1: -159841392324683824207757560
c2: 4620157173230199222146
c3: 634627619498303
c4: -16936271148
c5: 24480
skew: 360858.11
type: gnfs
# selected mechanically
rlim: 7900000
alim: 7900000
lpbr: 28
lpba: 28
mfbr: 53
mfba: 53
rlambda: 2.5
alambda: 2.5

*1 These parameters were not fully adjusted. The approximate expressions which were used for making the parameters are: d=log10(n); time=10^(d/21-4)[hours]; rlim=round(3*10^(d/37+3)); lpbr=floor(d/18+21); mfbr=floor(d/5+28); rlambda=floor(d/26+21)/10;

Efforts by ECM

The efforts by ECM to find small factors of this 127-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	118	Makoto Kamada	May 7, 2009
35	1e6	118 / 0
40	3e6	400	Dmitry Domanov	May 8, 2009
		400 / 2318
		/ 1918
45	11e6	0 / 4387 (556)
45	11e6	/ 4387 (556)
50	43e6	0 / 7538 (1251)
50	43e6	/ 7538 (1251)
55	11e7	0 / 17766 (3127)
55	11e7	/ 17766 (3127)

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

echo 3252125446710873989110474588642423409501343730321563303887977916287900309667323820346751457434688345006866071847720899280739381 | ecm -n -c 1918 3e6

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

echo 3252125446710873989110474588642423409501343730321563303887977916287900309667323820346751457434688345006866071847720899280739381 | ecm -n -c 4387 11e6

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

echo 3252125446710873989110474588642423409501343730321563303887977916287900309667323820346751457434688345006866071847720899280739381 | ecm -n -c 7538 43e6

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

echo 3252125446710873989110474588642423409501343730321563303887977916287900309667323820346751457434688345006866071847720899280739381 | ecm -n -c 17766 11e7

Contribution and Reservation

Status

How to factor it

ECM, P-1, P+1

GNFS

See also

Efforts by ECM

Submit polynomial for GNFS

Submit factors

Make reservation