Command line to find prime factors up to about 35-digit
echo 927980673273765753329287027289779035826404513063468161614756715575835974469454903486686796064263990177746275221214956124957610976664785111480951380989620121819 | ecm -n -c 825 1e6
Command line to find prime factors up to about 40-digit
echo 927980673273765753329287027289779035826404513063468161614756715575835974469454903486686796064263990177746275221214956124957610976664785111480951380989620121819 | ecm -n -c 2336 3e6
Command line to find prime factors up to about 45-digit
echo 927980673273765753329287027289779035826404513063468161614756715575835974469454903486686796064263990177746275221214956124957610976664785111480951380989620121819 | ecm -n -c 4479 11e6
Command line to find prime factors up to about 50-digit
echo 927980673273765753329287027289779035826404513063468161614756715575835974469454903486686796064263990177746275221214956124957610976664785111480951380989620121819 | ecm -n -c 7553 43e6