Command line to find prime factors up to about 45-digit
echo 5497668581305396532401907450640749152944535033751322787659919739277511451694105836805483559749328381395643428084855176167494056065079389 | ecm -n -c 3974 11e6
Command line to find prime factors up to about 50-digit
echo 5497668581305396532401907450640749152944535033751322787659919739277511451694105836805483559749328381395643428084855176167494056065079389 | ecm -n -c 7469 43e6
Command line to find prime factors up to about 55-digit
echo 5497668581305396532401907450640749152944535033751322787659919739277511451694105836805483559749328381395643428084855176167494056065079389 | ecm -n -c 17752 11e7
Command line to find prime factors up to about 60-digit
echo 5497668581305396532401907450640749152944535033751322787659919739277511451694105836805483559749328381395643428084855176167494056065079389 | ecm -n -c 42014 26e7