Command line to find prime factors up to about 35-digit
echo 165374992782288143099098664420190855135065524201790567845531019468290719579509530782801360420860492125166999904737069490397081057711442662739511913130562317785089919433785439437190546446326948947840039161333 | ecm -n -c 825 1e6
Command line to find prime factors up to about 40-digit
echo 165374992782288143099098664420190855135065524201790567845531019468290719579509530782801360420860492125166999904737069490397081057711442662739511913130562317785089919433785439437190546446326948947840039161333 | ecm -n -c 2336 3e6
Command line to find prime factors up to about 45-digit
echo 165374992782288143099098664420190855135065524201790567845531019468290719579509530782801360420860492125166999904737069490397081057711442662739511913130562317785089919433785439437190546446326948947840039161333 | ecm -n -c 4479 11e6
Command line to find prime factors up to about 50-digit
echo 165374992782288143099098664420190855135065524201790567845531019468290719579509530782801360420860492125166999904737069490397081057711442662739511913130562317785089919433785439437190546446326948947840039161333 | ecm -n -c 7553 43e6