Command line to find prime factors up to about 35-digit
echo 312676551044095351059812813407309169414678107486719833414303828794712728359329185472359657363335448150372357407809149332264741504437 | ecm -n -c 825 1e6
Command line to find prime factors up to about 40-digit
echo 312676551044095351059812813407309169414678107486719833414303828794712728359329185472359657363335448150372357407809149332264741504437 | ecm -n -c 2336 3e6
Command line to find prime factors up to about 45-digit
echo 312676551044095351059812813407309169414678107486719833414303828794712728359329185472359657363335448150372357407809149332264741504437 | ecm -n -c 4479 11e6
Command line to find prime factors up to about 50-digit
echo 312676551044095351059812813407309169414678107486719833414303828794712728359329185472359657363335448150372357407809149332264741504437 | ecm -n -c 7553 43e6