Command line to find prime factors up to about 35-digit
echo 7539350682064534726354614847395126163743754403124408363230016514691411173482221343944059630977326039444075416165574722301851700590741254789963085833154458478125104033 | ecm -n -c 825 1e6
Command line to find prime factors up to about 40-digit
echo 7539350682064534726354614847395126163743754403124408363230016514691411173482221343944059630977326039444075416165574722301851700590741254789963085833154458478125104033 | ecm -n -c 2336 3e6
Command line to find prime factors up to about 45-digit
echo 7539350682064534726354614847395126163743754403124408363230016514691411173482221343944059630977326039444075416165574722301851700590741254789963085833154458478125104033 | ecm -n -c 4479 11e6
Command line to find prime factors up to about 50-digit
echo 7539350682064534726354614847395126163743754403124408363230016514691411173482221343944059630977326039444075416165574722301851700590741254789963085833154458478125104033 | ecm -n -c 7553 43e6