Command line to find prime factors up to about 45-digit
echo 2109146572492664200833189888679432741141410698175846645555481358572215317086928676198576012243208092477835642711625515904058473068213645330965596764323782869122075528121860707850933347072239125936470876584497400850618846603 | ecm -n -c 3779 11e6
Command line to find prime factors up to about 50-digit
echo 2109146572492664200833189888679432741141410698175846645555481358572215317086928676198576012243208092477835642711625515904058473068213645330965596764323782869122075528121860707850933347072239125936470876584497400850618846603 | ecm -n -c 7396 43e6
Command line to find prime factors up to about 55-digit
echo 2109146572492664200833189888679432741141410698175846645555481358572215317086928676198576012243208092477835642711625515904058473068213645330965596764323782869122075528121860707850933347072239125936470876584497400850618846603 | ecm -n -c 17726 11e7
Command line to find prime factors up to about 60-digit
echo 2109146572492664200833189888679432741141410698175846645555481358572215317086928676198576012243208092477835642711625515904058473068213645330965596764323782869122075528121860707850933347072239125936470876584497400850618846603 | ecm -n -c 42006 26e7