I found that you can call 911 and 0. Both give some funny replies.
Are there more numbers not mentioned in the game?

Interestingly you can't call 112, which is what I tried. Maybe I should report it as a bug? ;)

According to the Wikipedia, the worldwide common emergency number 112 was only first introced in the US through the GSM system, which is the standard for mobile communication first deployed 1991 in Finland. The Wikipedia is a bit vague about its usage on US land lines - so the game is probably historically accurate.