Command line to find prime factors up to about 20-digit
echo 52540305819116930956808349785897320788889785558092422224013003441803811524703086188094107375466421678391648650754442319988838303366367328104067 | ecm -n -c 74 11e3
Command line to find prime factors up to about 25-digit
echo 52540305819116930956808349785897320788889785558092422224013003441803811524703086188094107375466421678391648650754442319988838303366367328104067 | ecm -n -c 214 5e4
Command line to find prime factors up to about 30-digit
echo 52540305819116930956808349785897320788889785558092422224013003441803811524703086188094107375466421678391648650754442319988838303366367328104067 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 52540305819116930956808349785897320788889785558092422224013003441803811524703086188094107375466421678391648650754442319988838303366367328104067 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 52540305819116930956808349785897320788889785558092422224013003441803811524703086188094107375466421678391648650754442319988838303366367328104067 | ecm -n -c 2350 3e6