Contribution and Reservation

(55·10¹⁹⁸-1)/9 =: 6(1)₁₉₈_<199>; = 3 · 139 · 37993 · [385727442226111897749630334599129494516319844044924791529571243820006418644903166947837425757724214823563113204503032655776430803523071750444948877753709086705490624652560389681218641191767631_<192>] SUBMIT/RESERVE

Status

Expression:	(55·10¹⁹⁸-1)/9
Composite Factor:	385727442226111897749630334599129494516319844044924791529571 243820006418644903166947837425757724214823563113204503032655 776430803523071750444948877753709086705490624652560389681218 641191767631 (192-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 201.04-digit and the GNFS difficulty is 191.59-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 61111_198.
Put the following polynomial file 61111_198.poly in there too.
And then, run "perl factMsieve.pl 61111_198".

61111_198.poly ^*1

n: 385727442226111897749630334599129494516319844044924791529571243820006418644903166947837425757724214823563113204503032655776430803523071750444948877753709086705490624652560389681218641191767631
m: 10000000000000000000000000000000000000000
deg: 5
c5: 11
c0: -20
skew: 1.13
type: snfs
lss: 1
rlim: 15700000
alim: 15700000
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 192-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	500	Erik Branger	Sep 14, 2009
		500 / 2350
		/ 1850
45	11e6	0 / 4370 (537)
45	11e6	/ 4370 (537)
50	43e6	0 / 7535 (1246)
50	43e6	/ 7535 (1246)
55	11e7	0 / 17766 (3126)
55	11e7	/ 17766 (3126)

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

echo 385727442226111897749630334599129494516319844044924791529571243820006418644903166947837425757724214823563113204503032655776430803523071750444948877753709086705490624652560389681218641191767631 | ecm -n -c 1850 3e6

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

echo 385727442226111897749630334599129494516319844044924791529571243820006418644903166947837425757724214823563113204503032655776430803523071750444948877753709086705490624652560389681218641191767631 | ecm -n -c 4370 11e6

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

echo 385727442226111897749630334599129494516319844044924791529571243820006418644903166947837425757724214823563113204503032655776430803523071750444948877753709086705490624652560389681218641191767631 | ecm -n -c 7535 43e6

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

echo 385727442226111897749630334599129494516319844044924791529571243820006418644903166947837425757724214823563113204503032655776430803523071750444948877753709086705490624652560389681218641191767631 | ecm -n -c 17766 11e7

Submit factors

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