Contribution and Reservation

(64·10²⁴⁰+53)/9 =: 7(1)₂₃₉7_<241>; = 13 · 239 · 7100971 · 4599759023_<10> · 791453439932771621_<18> · [88535617617913709618208984739081043580467747067315043437761675886096793169240102007542777950207130512948230488725631860687831121797985105606811766297578494586016100617450953087187889103440008699793328167_<203>] SUBMIT/RESERVE

Status

Expression:	(64·10²⁴⁰+53)/9
Composite Factor:	885356176179137096182089847390810435804677470673150434377616 758860967931692401020075427779502071305129482304887256318606 878311217979851056068117662975784945860161006174509530871878 89103440008699793328167 (203-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 241.81-digit and the GNFS difficulty is 202.95-digit. SNFS must be faster than GNFS. It will take about 479 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 71117_240.
Put the following polynomial file 71117_240.poly in there too.
And then, run "perl factMsieve.pl 71117_240".

71117_240.poly ^*1

n: 88535617617913709618208984739081043580467747067315043437761675886096793169240102007542777950207130512948230488725631860687831121797985105606811766297578494586016100617450953087187889103440008699793328167
m: 20000000000000000000000000000000000000000
deg: 6
c6: 1
c0: 53
skew: 1.94
type: snfs
lss: 1
rlim: 75000000
alim: 75000000
lpbr: 30
lpba: 30
mfbr: 61
mfba: 61
rlambda: 2.7
alambda: 2.7

*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 203-digit composite number so far are as follows. According to the reports, unknown prime factors of this composite number are probably 20-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
20	11e3	74	Max Dettweiler	Mar 6, 2009
20	11e3	74 / 74
25	5e4	0 / 204
25	5e4	/ 204
30	25e4	0 / 430 (48)
30	25e4	/ 430 (48)
35	1e6	0 / 904 (118)
35	1e6	/ 904 (118)
40	3e6	0 / 2350 (322)
40	3e6	/ 2350 (322)

Command line to find prime factors up to about 25-digit

echo 88535617617913709618208984739081043580467747067315043437761675886096793169240102007542777950207130512948230488725631860687831121797985105606811766297578494586016100617450953087187889103440008699793328167 | ecm -n -c 204 5e4

Command line to find prime factors up to about 30-digit

echo 88535617617913709618208984739081043580467747067315043437761675886096793169240102007542777950207130512948230488725631860687831121797985105606811766297578494586016100617450953087187889103440008699793328167 | ecm -n -c 430 25e4

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

echo 88535617617913709618208984739081043580467747067315043437761675886096793169240102007542777950207130512948230488725631860687831121797985105606811766297578494586016100617450953087187889103440008699793328167 | ecm -n -c 904 1e6

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

echo 88535617617913709618208984739081043580467747067315043437761675886096793169240102007542777950207130512948230488725631860687831121797985105606811766297578494586016100617450953087187889103440008699793328167 | ecm -n -c 2350 3e6

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