Command line to find prime factors up to about 35-digit
echo 2000607937998553847867999279634970191353296469676094338977065348682204772584145822075385889630675336835542521250884511837679951472229175024113083434303576334713107060864222400713954125449693133631 | ecm -n -c 786 1e6
Command line to find prime factors up to about 40-digit
echo 2000607937998553847867999279634970191353296469676094338977065348682204772584145822075385889630675336835542521250884511837679951472229175024113083434303576334713107060864222400713954125449693133631 | ecm -n -c 2318 3e6
Command line to find prime factors up to about 45-digit
echo 2000607937998553847867999279634970191353296469676094338977065348682204772584145822075385889630675336835542521250884511837679951472229175024113083434303576334713107060864222400713954125449693133631 | ecm -n -c 4475 11e6
Command line to find prime factors up to about 50-digit
echo 2000607937998553847867999279634970191353296469676094338977065348682204772584145822075385889630675336835542521250884511837679951472229175024113083434303576334713107060864222400713954125449693133631 | ecm -n -c 7553 43e6