Replace it with a different wireless router.
Having to power cycle home grade routers is normal, every 2 days is excessive, 2 to 3 months is more normal.
If you feel adventurous try flashing the bios with the newest available version. The factory flash version may need updating, the original flash may have been bad.
Most of the time this kind of hang is caused by a buffer overrun. Sometimes its caused by internal code not clearing a buffer somewhere caused either by sloppy coding, or by a routine not being called (or not working at all) caused by a bad flash.
Second most likely cause is bad power, normally the transformer provided with the unit.
Sometimes this is caused by internet side traffic, either accidentally (a buffer overrun problem again) or deliberately.