Contribution and Reservation

(19·10²⁰²-7)/3 =: 6(3)₂₀₁1_<203>; = 21957493 · [2884360857286090599383697097539019292108317344486154832581904197047146198945996855530516773173209406617291570277778675977869301077920568315031835981153829052038560747045818633909314389094116224167_<196>] SUBMIT/RESERVE

Status

Expression:	(19·10²⁰²-7)/3
Composite Factor:	288436085728609059938369709753901929210831734448615483258190 419704714619894599685553051677317320940661729157027777867597 786930107792056831503183598115382905203856074704581863390931 4389094116224167 (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 204.18-digit and the GNFS difficulty is 195.46-digit. SNFS must be faster than GNFS. It will take about 27 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 63331_202.
Put the following polynomial file 63331_202.poly in there too.
And then, run "perl factMsieve.pl 63331_202".

63331_202.poly ^*1

n: 2884360857286090599383697097539019292108317344486154832581904197047146198945996855530516773173209406617291570277778675977869301077920568315031835981153829052038560747045818633909314389094116224167
m: 20000000000000000000000000000000000000000
deg: 5
c5: 475
c0: -56
skew: 0.65
type: snfs
lss: 1
rlim: 17700000
alim: 17700000
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 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	May 28, 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 2884360857286090599383697097539019292108317344486154832581904197047146198945996855530516773173209406617291570277778675977869301077920568315031835981153829052038560747045818633909314389094116224167 | ecm -n -c 786 1e6

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

echo 2884360857286090599383697097539019292108317344486154832581904197047146198945996855530516773173209406617291570277778675977869301077920568315031835981153829052038560747045818633909314389094116224167 | ecm -n -c 2318 3e6

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

echo 2884360857286090599383697097539019292108317344486154832581904197047146198945996855530516773173209406617291570277778675977869301077920568315031835981153829052038560747045818633909314389094116224167 | ecm -n -c 4475 11e6

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

echo 2884360857286090599383697097539019292108317344486154832581904197047146198945996855530516773173209406617291570277778675977869301077920568315031835981153829052038560747045818633909314389094116224167 | ecm -n -c 7553 43e6

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