"There are five of us."
Translation:Vi är fem stycken.
Yup, both пять штук and нас пятеро. To be fair it isn't used very often for people, but it's certainly possible (the sentence here is good but we usually just say Han har tre barn 'He has three kids' without stycken).
Note that styck and stycken aren't really the same word – styck is used e.g. to say De kostar fem kronor styck 'They cost 5SEK a piece' and stycken is used like here.
I have found (in Skåne at least!) that it is applied to people all the time! Especially in written form. eg. Meet us at the pub? Vi är 5st. Or various other situations. People often just say Vi är 5 as well though.
I was kinda surprised how often I have come across it. Despite having read here that it could be used for people I was still uncomfortable with using it for the reason Baba7249 describes. Getting used to it now though.