Contribution and Reservation

(26·10¹⁹⁸+1)/9 =: 2(8)₁₉₇9_<199>; = 3 · 77279 · [12460862109537687637818333091305050051928246521861863675292938093957775889477904255528189585307301633858654524035804849479974675694082001099431449203055978505971388902068646889361443121196741197_<194>] SUBMIT/RESERVE

Status

Expression:	(26·10¹⁹⁸+1)/9
Composite Factor:	124608621095376876378183330913050500519282465218618636752929 380939577758894779042555281895853073016338586545240358048494 799746756940820010994314492030559785059713889020686468893614 43121196741197 (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 201.11-digit and the GNFS difficulty is 193.10-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 28889_198.
Put the following polynomial file 28889_198.poly in there too.
And then, run "perl factMsieve.pl 28889_198".

28889_198.poly ^*1

n: 12460862109537687637818333091305050051928246521861863675292938093957775889477904255528189585307301633858654524035804849479974675694082001099431449203055978505971388902068646889361443121196741197
m: 10000000000000000000000000000000000000000
deg: 5
c5: 13
c0: 50
skew: 1.31
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 194-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	1180	Max Dettweiler	Aug 16, 2009
35	1e6	1180 / 825
40	3e6	0 / 2014
40	3e6	/ 2014
45	11e6	0 / 4424 (584)
45	11e6	/ 4424 (584)
50	43e6	0 / 7546 (1262)
50	43e6	/ 7546 (1262)
55	11e7	0 / 17768 (3131)
55	11e7	/ 17768 (3131)

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

echo 12460862109537687637818333091305050051928246521861863675292938093957775889477904255528189585307301633858654524035804849479974675694082001099431449203055978505971388902068646889361443121196741197 | ecm -n -c 2014 3e6

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

echo 12460862109537687637818333091305050051928246521861863675292938093957775889477904255528189585307301633858654524035804849479974675694082001099431449203055978505971388902068646889361443121196741197 | ecm -n -c 4424 11e6

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

echo 12460862109537687637818333091305050051928246521861863675292938093957775889477904255528189585307301633858654524035804849479974675694082001099431449203055978505971388902068646889361443121196741197 | ecm -n -c 7546 43e6

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

echo 12460862109537687637818333091305050051928246521861863675292938093957775889477904255528189585307301633858654524035804849479974675694082001099431449203055978505971388902068646889361443121196741197 | ecm -n -c 17768 11e7

Submit factors

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