Command line to find prime factors up to about 20-digit
echo 12645599499413645861011458910262370031272109042994557742275577331055686579021016962488611833408759921161141343727131690614773747616744415442996963184471624741469687973802997309583 | ecm -n -c 74 11e3
Command line to find prime factors up to about 25-digit
echo 12645599499413645861011458910262370031272109042994557742275577331055686579021016962488611833408759921161141343727131690614773747616744415442996963184471624741469687973802997309583 | ecm -n -c 214 5e4
Command line to find prime factors up to about 30-digit
echo 12645599499413645861011458910262370031272109042994557742275577331055686579021016962488611833408759921161141343727131690614773747616744415442996963184471624741469687973802997309583 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 12645599499413645861011458910262370031272109042994557742275577331055686579021016962488611833408759921161141343727131690614773747616744415442996963184471624741469687973802997309583 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 12645599499413645861011458910262370031272109042994557742275577331055686579021016962488611833408759921161141343727131690614773747616744415442996963184471624741469687973802997309583 | ecm -n -c 2350 3e6