Contribution and Reservation

(44·10¹⁹⁹-17)/9 =: 4(8)₁₉₈7_<200>; = 31 · 173 · [9115959143928564029253941616425300930242194459983011167049951312490935836078480120993639546688213479188679636190357801396399196138148217208444693061512006132554333188306710589015269231566080344749_<196>] SUBMIT/RESERVE

Status

Expression:	(44·10¹⁹⁹-17)/9
Composite Factor:	911595914392856402925394161642530093024219445998301116704995 131249093583607848012099363954668821347918867963619035780139 639919613814821720844469306151200613255433318830671058901526 9231566080344749 (196-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 201.34-digit and the GNFS difficulty is 195.96-digit. SNFS must be faster than GNFS. It will take about 21 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 48887_199.
Put the following polynomial file 48887_199.poly in there too.
And then, run "perl factMsieve.pl 48887_199".

48887_199.poly ^*1

n: 9115959143928564029253941616425300930242194459983011167049951312490935836078480120993639546688213479188679636190357801396399196138148217208444693061512006132554333188306710589015269231566080344749
m: 10000000000000000000000000000000000000000
deg: 5
c5: 22
c0: -85
skew: 1.31
type: snfs
lss: 1
rlim: 15900000
alim: 15900000
lpbr: 29
lpba: 29
mfbr: 56
mfba: 56
rlambda: 2.6
alambda: 2.6

*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 196-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	Feb 27, 2009
		786	Wataru Sakai	Aug 12, 2009
		904 / 904
40	3e6	0 / 2104
40	3e6	/ 2104
45	11e6	0 / 4439 (610)
45	11e6	/ 4439 (610)
50	43e6	0 / 7548 (1266)
50	43e6	/ 7548 (1266)
55	11e7	0 / 17769 (3131)
55	11e7	/ 17769 (3131)

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

echo 9115959143928564029253941616425300930242194459983011167049951312490935836078480120993639546688213479188679636190357801396399196138148217208444693061512006132554333188306710589015269231566080344749 | ecm -n -c 2104 3e6

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

echo 9115959143928564029253941616425300930242194459983011167049951312490935836078480120993639546688213479188679636190357801396399196138148217208444693061512006132554333188306710589015269231566080344749 | ecm -n -c 4439 11e6

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

echo 9115959143928564029253941616425300930242194459983011167049951312490935836078480120993639546688213479188679636190357801396399196138148217208444693061512006132554333188306710589015269231566080344749 | ecm -n -c 7548 43e6

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

echo 9115959143928564029253941616425300930242194459983011167049951312490935836078480120993639546688213479188679636190357801396399196138148217208444693061512006132554333188306710589015269231566080344749 | ecm -n -c 17769 11e7

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