Command line to find prime factors up to about 35-digit
echo 3354236512997066115957206225930999743339925877410497521481149353858557833379730711016115321338655398055287404773435653056412792384846025310346612111629443231904356775596779664016308395618811651 | ecm -n -c 825 1e6
Command line to find prime factors up to about 40-digit
echo 3354236512997066115957206225930999743339925877410497521481149353858557833379730711016115321338655398055287404773435653056412792384846025310346612111629443231904356775596779664016308395618811651 | ecm -n -c 2336 3e6
Command line to find prime factors up to about 45-digit
echo 3354236512997066115957206225930999743339925877410497521481149353858557833379730711016115321338655398055287404773435653056412792384846025310346612111629443231904356775596779664016308395618811651 | ecm -n -c 4479 11e6
Command line to find prime factors up to about 50-digit
echo 3354236512997066115957206225930999743339925877410497521481149353858557833379730711016115321338655398055287404773435653056412792384846025310346612111629443231904356775596779664016308395618811651 | ecm -n -c 7553 43e6