Command line to find prime factors up to about 20-digit
echo 6005746479913446404346726758032944408081363856952174853123170919963824951307811742336904849137778594825101331685928673270285489469708151517506806792204469486897000526475130709847 | ecm -n -c 74 11e3
Command line to find prime factors up to about 25-digit
echo 6005746479913446404346726758032944408081363856952174853123170919963824951307811742336904849137778594825101331685928673270285489469708151517506806792204469486897000526475130709847 | ecm -n -c 214 5e4
Command line to find prime factors up to about 30-digit
echo 6005746479913446404346726758032944408081363856952174853123170919963824951307811742336904849137778594825101331685928673270285489469708151517506806792204469486897000526475130709847 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 6005746479913446404346726758032944408081363856952174853123170919963824951307811742336904849137778594825101331685928673270285489469708151517506806792204469486897000526475130709847 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 6005746479913446404346726758032944408081363856952174853123170919963824951307811742336904849137778594825101331685928673270285489469708151517506806792204469486897000526475130709847 | ecm -n -c 2350 3e6