Command line to find prime factors up to about 40-digit
echo 489241024496907354315699990163522497568807868639472158427158410636880445374402685926600142762794996201973895068523081010022271307068961 | ecm -n -c 1850 3e6
Command line to find prime factors up to about 45-digit
echo 489241024496907354315699990163522497568807868639472158427158410636880445374402685926600142762794996201973895068523081010022271307068961 | ecm -n -c 4370 11e6
Command line to find prime factors up to about 50-digit
echo 489241024496907354315699990163522497568807868639472158427158410636880445374402685926600142762794996201973895068523081010022271307068961 | ecm -n -c 7535 43e6
Command line to find prime factors up to about 55-digit
echo 489241024496907354315699990163522497568807868639472158427158410636880445374402685926600142762794996201973895068523081010022271307068961 | ecm -n -c 17766 11e7