Contribution and Reservation

(53·10¹⁹⁹-17)/9 =: 5(8)₁₉₈7_<200>; = 3 · 19 · 29 · 2087 · [17070178305098131140775216059340320060689959214834925417331236084785192258036422542825937098840744866570629199364512690373150554882249749012015118767053873064028402973058201996830808670065951117_<194>] SUBMIT/RESERVE

Status

Expression:	(53·10¹⁹⁹-17)/9
Composite Factor:	170701783050981311407752160593403200606899592148349254173312 360847851922580364225428259370988407448665706291993645126903 731505548822497490120151187670538730640284029730582019968308 08670065951117 (194-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 201.72-digit and the GNFS difficulty is 193.23-digit. SNFS must be faster than GNFS. It will take about 22 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 58887_199.
Put the following polynomial file 58887_199.poly in there too.
And then, run "perl factMsieve.pl 58887_199".

58887_199.poly ^*1

n: 17070178305098131140775216059340320060689959214834925417331236084785192258036422542825937098840744866570629199364512690373150554882249749012015118767053873064028402973058201996830808670065951117
m: 10000000000000000000000000000000000000000
deg: 5
c5: 53
c0: -170
skew: 1.26
type: snfs
lss: 1
rlim: 16100000
alim: 16100000
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 194-digit composite number so far are as follows. According to the reports, unknown prime factors of this composite number are probably 30-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
30	25e4	0 / 0
35	1e6	118	Makoto Kamada	Apr 22, 2009
		118 / 904
		/ 786
40	3e6	0 / 2318 (280)
40	3e6	/ 2318 (280)
45	11e6	0 / 4475 (672)
45	11e6	/ 4475 (672)
50	43e6	0 / 7553 (1276)
50	43e6	/ 7553 (1276)

Command line to find prime factors up to about 35-digit

echo 17070178305098131140775216059340320060689959214834925417331236084785192258036422542825937098840744866570629199364512690373150554882249749012015118767053873064028402973058201996830808670065951117 | ecm -n -c 786 1e6

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

echo 17070178305098131140775216059340320060689959214834925417331236084785192258036422542825937098840744866570629199364512690373150554882249749012015118767053873064028402973058201996830808670065951117 | ecm -n -c 2318 3e6

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

echo 17070178305098131140775216059340320060689959214834925417331236084785192258036422542825937098840744866570629199364512690373150554882249749012015118767053873064028402973058201996830808670065951117 | ecm -n -c 4475 11e6

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

echo 17070178305098131140775216059340320060689959214834925417331236084785192258036422542825937098840744866570629199364512690373150554882249749012015118767053873064028402973058201996830808670065951117 | ecm -n -c 7553 43e6

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