Command line to find prime factors up to about 35-digit
echo 2451614495742798461237609954389542919894362289056877538222666783895045972734945304654442736252203756409045872358242450455580423798000910100651491836954045773901763462948420540470156451674925896917129041325046661 | ecm -n -c 825 1e6
Command line to find prime factors up to about 40-digit
echo 2451614495742798461237609954389542919894362289056877538222666783895045972734945304654442736252203756409045872358242450455580423798000910100651491836954045773901763462948420540470156451674925896917129041325046661 | ecm -n -c 2336 3e6
Command line to find prime factors up to about 45-digit
echo 2451614495742798461237609954389542919894362289056877538222666783895045972734945304654442736252203756409045872358242450455580423798000910100651491836954045773901763462948420540470156451674925896917129041325046661 | ecm -n -c 4479 11e6
Command line to find prime factors up to about 50-digit
echo 2451614495742798461237609954389542919894362289056877538222666783895045972734945304654442736252203756409045872358242450455580423798000910100651491836954045773901763462948420540470156451674925896917129041325046661 | ecm -n -c 7553 43e6