Command line to find prime factors up to about 25-digit
echo 23407694621966785307982015594726839526771304579314948599091374903091709675792721990819469156525447745289275395521400548785760972171530737229477 | ecm -n -c 204 5e4
Command line to find prime factors up to about 30-digit
echo 23407694621966785307982015594726839526771304579314948599091374903091709675792721990819469156525447745289275395521400548785760972171530737229477 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 23407694621966785307982015594726839526771304579314948599091374903091709675792721990819469156525447745289275395521400548785760972171530737229477 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 23407694621966785307982015594726839526771304579314948599091374903091709675792721990819469156525447745289275395521400548785760972171530737229477 | ecm -n -c 2350 3e6