Command line to find prime factors up to about 45-digit
echo 8352907746168398011443299848280289570921069039547334545791304320660978286374079510610485710810188699787131993124320694556975513676470616487776200275463862234690663300979431056557045527749199 | ecm -n -c 3872 11e6
Command line to find prime factors up to about 50-digit
echo 8352907746168398011443299848280289570921069039547334545791304320660978286374079510610485710810188699787131993124320694556975513676470616487776200275463862234690663300979431056557045527749199 | ecm -n -c 7452 43e6
Command line to find prime factors up to about 55-digit
echo 8352907746168398011443299848280289570921069039547334545791304320660978286374079510610485710810188699787131993124320694556975513676470616487776200275463862234690663300979431056557045527749199 | ecm -n -c 17749 11e7
Command line to find prime factors up to about 60-digit
echo 8352907746168398011443299848280289570921069039547334545791304320660978286374079510610485710810188699787131993124320694556975513676470616487776200275463862234690663300979431056557045527749199 | ecm -n -c 42014 26e7