Command line to find prime factors up to about 50-digit
echo 3663098565111345395412929971728350097530716199796536338138921821753864966157300030614431362264492489238686784881314038315456171995557481 | ecm -n -c 6521 43e6
Command line to find prime factors up to about 55-digit
echo 3663098565111345395412929971728350097530716199796536338138921821753864966157300030614431362264492489238686784881314038315456171995557481 | ecm -n -c 17485 11e7
Command line to find prime factors up to about 60-digit
echo 3663098565111345395412929971728350097530716199796536338138921821753864966157300030614431362264492489238686784881314038315456171995557481 | ecm -n -c 41946 26e7
Command line to find prime factors up to about 65-digit
echo 3663098565111345395412929971728350097530716199796536338138921821753864966157300030614431362264492489238686784881314038315456171995557481 | ecm -n -c 69397 85e7