Command line to find prime factors up to about 20-digit
echo 142708694217422199534850030122643805499631928056170315471407324815022708521964769226911700650796214324193854708645641470420730443346540541244548607710671601693 | ecm -n -c 74 11e3
Command line to find prime factors up to about 25-digit
echo 142708694217422199534850030122643805499631928056170315471407324815022708521964769226911700650796214324193854708645641470420730443346540541244548607710671601693 | ecm -n -c 214 5e4
Command line to find prime factors up to about 30-digit
echo 142708694217422199534850030122643805499631928056170315471407324815022708521964769226911700650796214324193854708645641470420730443346540541244548607710671601693 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 142708694217422199534850030122643805499631928056170315471407324815022708521964769226911700650796214324193854708645641470420730443346540541244548607710671601693 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 142708694217422199534850030122643805499631928056170315471407324815022708521964769226911700650796214324193854708645641470420730443346540541244548607710671601693 | ecm -n -c 2350 3e6