outsiders in my router

[IFHTT]

You should change your password from the default, especially if it's got wireless support. Default passwords are a bad idea to leave intact, unless you can be absolutely confident that nobody's ever going to have a chance to change it out from under you.

But no, most routers don't expose the management interface to the outside, unless you specifically tell them to.

It's especially a good idea to change the password since a lot of consumer grade routers use a blank pass as default.