Command line to find prime factors up to about 35-digit
echo 66328868983150052035365562676535637510278958055717901183165153062867411884374816141527575937460282996244280551811527859913031002126086752300747235755286267422223171302077315691995804639779609201951305578907 | ecm -n -c 825 1e6
Command line to find prime factors up to about 40-digit
echo 66328868983150052035365562676535637510278958055717901183165153062867411884374816141527575937460282996244280551811527859913031002126086752300747235755286267422223171302077315691995804639779609201951305578907 | ecm -n -c 2336 3e6
Command line to find prime factors up to about 45-digit
echo 66328868983150052035365562676535637510278958055717901183165153062867411884374816141527575937460282996244280551811527859913031002126086752300747235755286267422223171302077315691995804639779609201951305578907 | ecm -n -c 4479 11e6
Command line to find prime factors up to about 50-digit
echo 66328868983150052035365562676535637510278958055717901183165153062867411884374816141527575937460282996244280551811527859913031002126086752300747235755286267422223171302077315691995804639779609201951305578907 | ecm -n -c 7553 43e6