Command line to find prime factors up to about 35-digit
echo 315100028245168413730164547912666490544882273079051501825528218827081332903514884049893121986958096917511944946111063802903815642455242090360685290200921648196299277805766036401233373029049 | ecm -n -c 825 1e6
Command line to find prime factors up to about 40-digit
echo 315100028245168413730164547912666490544882273079051501825528218827081332903514884049893121986958096917511944946111063802903815642455242090360685290200921648196299277805766036401233373029049 | ecm -n -c 2336 3e6
Command line to find prime factors up to about 45-digit
echo 315100028245168413730164547912666490544882273079051501825528218827081332903514884049893121986958096917511944946111063802903815642455242090360685290200921648196299277805766036401233373029049 | ecm -n -c 4479 11e6
Command line to find prime factors up to about 50-digit
echo 315100028245168413730164547912666490544882273079051501825528218827081332903514884049893121986958096917511944946111063802903815642455242090360685290200921648196299277805766036401233373029049 | ecm -n -c 7553 43e6