Command line to find prime factors up to about 20-digit
echo 979768084237686341427025126835042332880338711169990014775384141754487482708879674297990154140752633041822746156567383327838548383521206317631889 | ecm -n -c 74 11e3
Command line to find prime factors up to about 25-digit
echo 979768084237686341427025126835042332880338711169990014775384141754487482708879674297990154140752633041822746156567383327838548383521206317631889 | ecm -n -c 214 5e4
Command line to find prime factors up to about 30-digit
echo 979768084237686341427025126835042332880338711169990014775384141754487482708879674297990154140752633041822746156567383327838548383521206317631889 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 979768084237686341427025126835042332880338711169990014775384141754487482708879674297990154140752633041822746156567383327838548383521206317631889 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 979768084237686341427025126835042332880338711169990014775384141754487482708879674297990154140752633041822746156567383327838548383521206317631889 | ecm -n -c 2350 3e6