Command line to find prime factors up to about 20-digit
echo 129470141639261904582910502648673504954818042429594469935912076340715398455793050915999628425751324181879131033727312160885598364957151648245119 | ecm -n -c 74 11e3
Command line to find prime factors up to about 25-digit
echo 129470141639261904582910502648673504954818042429594469935912076340715398455793050915999628425751324181879131033727312160885598364957151648245119 | ecm -n -c 214 5e4
Command line to find prime factors up to about 30-digit
echo 129470141639261904582910502648673504954818042429594469935912076340715398455793050915999628425751324181879131033727312160885598364957151648245119 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 129470141639261904582910502648673504954818042429594469935912076340715398455793050915999628425751324181879131033727312160885598364957151648245119 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 129470141639261904582910502648673504954818042429594469935912076340715398455793050915999628425751324181879131033727312160885598364957151648245119 | ecm -n -c 2350 3e6