Command line to find prime factors up to about 25-digit
echo 6307375813657836245391384948506221181503127938158011353424807273289364847995843369732164212319516764115100059956802815471354573467133201821 | ecm -n -c 204 5e4
Command line to find prime factors up to about 30-digit
echo 6307375813657836245391384948506221181503127938158011353424807273289364847995843369732164212319516764115100059956802815471354573467133201821 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 6307375813657836245391384948506221181503127938158011353424807273289364847995843369732164212319516764115100059956802815471354573467133201821 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 6307375813657836245391384948506221181503127938158011353424807273289364847995843369732164212319516764115100059956802815471354573467133201821 | ecm -n -c 2350 3e6