Command line to find prime factors up to about 20-digit
echo 249206836913338582402714107074746799571734044325296092711534363744295257205810248398133741818941193014129918977889302449676199063062222089191219936686253000529225700233 | ecm -n -c 74 11e3
Command line to find prime factors up to about 25-digit
echo 249206836913338582402714107074746799571734044325296092711534363744295257205810248398133741818941193014129918977889302449676199063062222089191219936686253000529225700233 | ecm -n -c 214 5e4
Command line to find prime factors up to about 30-digit
echo 249206836913338582402714107074746799571734044325296092711534363744295257205810248398133741818941193014129918977889302449676199063062222089191219936686253000529225700233 | ecm -n -c 430 25e4
Command line to find prime factors up to about 35-digit
echo 249206836913338582402714107074746799571734044325296092711534363744295257205810248398133741818941193014129918977889302449676199063062222089191219936686253000529225700233 | ecm -n -c 904 1e6
Command line to find prime factors up to about 40-digit
echo 249206836913338582402714107074746799571734044325296092711534363744295257205810248398133741818941193014129918977889302449676199063062222089191219936686253000529225700233 | ecm -n -c 2350 3e6