Command line to find prime factors up to about 25-digit
echo 2941459169441153770242969053005832065201316302143215834155515413844401715963566240400660673794392656131763792144452441225561250387655038256033616727 | ecm -n -c 204 5e4
Command line to find prime factors up to about 30-digit
echo 2941459169441153770242969053005832065201316302143215834155515413844401715963566240400660673794392656131763792144452441225561250387655038256033616727 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 2941459169441153770242969053005832065201316302143215834155515413844401715963566240400660673794392656131763792144452441225561250387655038256033616727 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 2941459169441153770242969053005832065201316302143215834155515413844401715963566240400660673794392656131763792144452441225561250387655038256033616727 | ecm -n -c 2350 3e6