Contribution and Reservation

(35·10¹⁹⁹-17)/9 =: 3(8)₁₉₈7_<200>; = 37² · 10733 · 1474787 · 40926981270737_<14> · 67943981069963573_<17> · 104941293006996173973083_<24> · [6149850280939304810500832045132117855102230364543333119052900871783265588595924318325048357224804689724720278116290555760981488260511_<133>] SUBMIT/RESERVE

Status

Expression:	(35·10¹⁹⁹-17)/9
Composite Factor:	614985028093930481050083204513211785510223036454333311905290 087178326558859592431832504835722480468972472027811629055576 0981488260511 (133-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 200.85-digit and the GNFS difficulty is 132.79-digit. GNFS must be faster than SNFS. It will take about 9 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 38887_199.
Put the following polynomial file 38887_199.poly in there too.
And then, run "perl factMsieve.pl 38887_199".

38887_199.poly ^*1

# Murphy_E = 5.859619e-11, selected by Jeff Gilchrist
n: 6149850280939304810500832045132117855102230364543333119052900871783265588595924318325048357224804689724720278116290555760981488260511
Y0: -42941243770366882559423751
Y1: 550936212080287
c0: 262859614668031328693105541259940
c1: 4249475897406715426521387908
c2: -3530176515760468299455
c3: -65325844540525418
c4: 23309527290
c5: 42120
skew: 514434.25
type: gnfs
# selected mechanically
rlim: 11600000
alim: 11600000
lpbr: 28
lpba: 28
mfbr: 54
mfba: 54
rlambda: 2.6
alambda: 2.6

*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 133-digit composite number so far are as follows. According to the reports, unknown prime factors of this composite number are probably 40-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
40	3e6	50	Erik Branger	May 12, 2009
		450	Erik Branger	May 13, 2009
		1836	Wataru Sakai	Jul 31, 2009
		2336 / 2336
45	11e6	0 / 3962
45	11e6	/ 3962
50	43e6	0 / 7465 (1130)
50	43e6	/ 7465 (1130)
55	11e7	0 / 17751 (3097)
55	11e7	/ 17751 (3097)
60	26e7	0 / 42014 (7636)
60	26e7	/ 42014 (7636)

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

echo 6149850280939304810500832045132117855102230364543333119052900871783265588595924318325048357224804689724720278116290555760981488260511 | ecm -n -c 3962 11e6

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

echo 6149850280939304810500832045132117855102230364543333119052900871783265588595924318325048357224804689724720278116290555760981488260511 | ecm -n -c 7465 43e6

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

echo 6149850280939304810500832045132117855102230364543333119052900871783265588595924318325048357224804689724720278116290555760981488260511 | ecm -n -c 17751 11e7

Command line to find prime factors up to about 60-digit

echo 6149850280939304810500832045132117855102230364543333119052900871783265588595924318325048357224804689724720278116290555760981488260511 | ecm -n -c 42014 26e7

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