Command line to find prime factors up to about 40-digit
echo 30834343458224868068173132331884236046663965292046023323100292886352755369376690028707988748583294944309834281749699131403265831658240853637654512159523718149 | ecm -n -c 1573 3e6
Command line to find prime factors up to about 45-digit
echo 30834343458224868068173132331884236046663965292046023323100292886352755369376690028707988748583294944309834281749699131403265831658240853637654512159523718149 | ecm -n -c 4326 11e6
Command line to find prime factors up to about 50-digit
echo 30834343458224868068173132331884236046663965292046023323100292886352755369376690028707988748583294944309834281749699131403265831658240853637654512159523718149 | ecm -n -c 7529 43e6
Command line to find prime factors up to about 55-digit
echo 30834343458224868068173132331884236046663965292046023323100292886352755369376690028707988748583294944309834281749699131403265831658240853637654512159523718149 | ecm -n -c 17765 11e7