Command line to find prime factors up to about 35-digit
echo 43999573131412731821244310394957477165025040198739128869945884369893758915884725692824645975690256003517293893303349646548705176793462967323476927059009461201813421610375868592425469990878490457169133 | ecm -n -c 786 1e6
Command line to find prime factors up to about 40-digit
echo 43999573131412731821244310394957477165025040198739128869945884369893758915884725692824645975690256003517293893303349646548705176793462967323476927059009461201813421610375868592425469990878490457169133 | ecm -n -c 2318 3e6
Command line to find prime factors up to about 45-digit
echo 43999573131412731821244310394957477165025040198739128869945884369893758915884725692824645975690256003517293893303349646548705176793462967323476927059009461201813421610375868592425469990878490457169133 | ecm -n -c 4475 11e6
Command line to find prime factors up to about 50-digit
echo 43999573131412731821244310394957477165025040198739128869945884369893758915884725692824645975690256003517293893303349646548705176793462967323476927059009461201813421610375868592425469990878490457169133 | ecm -n -c 7553 43e6