Command line to find prime factors up to about 20-digit
echo 17510560952549755008743199673418615188851096604511285390325536941407680040938042248964700586456148081747198773817682577101323203028375696195178401061777525677306207784765637 | ecm -n -c 74 11e3
Command line to find prime factors up to about 25-digit
echo 17510560952549755008743199673418615188851096604511285390325536941407680040938042248964700586456148081747198773817682577101323203028375696195178401061777525677306207784765637 | ecm -n -c 214 5e4
Command line to find prime factors up to about 30-digit
echo 17510560952549755008743199673418615188851096604511285390325536941407680040938042248964700586456148081747198773817682577101323203028375696195178401061777525677306207784765637 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 17510560952549755008743199673418615188851096604511285390325536941407680040938042248964700586456148081747198773817682577101323203028375696195178401061777525677306207784765637 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 17510560952549755008743199673418615188851096604511285390325536941407680040938042248964700586456148081747198773817682577101323203028375696195178401061777525677306207784765637 | ecm -n -c 2350 3e6