Command line to find prime factors up to about 35-digit
echo 3168581309238129920793115568758706086877473473784524015169419125840862264939068727730473044059341627805109523105568060525584600520018823558205363621474284067247784478780939694140124061977013363 | ecm -n -c 825 1e6
Command line to find prime factors up to about 40-digit
echo 3168581309238129920793115568758706086877473473784524015169419125840862264939068727730473044059341627805109523105568060525584600520018823558205363621474284067247784478780939694140124061977013363 | ecm -n -c 2336 3e6
Command line to find prime factors up to about 45-digit
echo 3168581309238129920793115568758706086877473473784524015169419125840862264939068727730473044059341627805109523105568060525584600520018823558205363621474284067247784478780939694140124061977013363 | ecm -n -c 4479 11e6
Command line to find prime factors up to about 50-digit
echo 3168581309238129920793115568758706086877473473784524015169419125840862264939068727730473044059341627805109523105568060525584600520018823558205363621474284067247784478780939694140124061977013363 | ecm -n -c 7553 43e6