luja
Unable to answer "What street does the (house) number 555 belong to?" for https://osm.org/way/28933482 via StreetComplete 33.1:

all buildings in CERN have chaotic numbers like the houses in an old village. The address would be "The Village 54" in case of "The village" of the bbc tv series prisoner :-). 

The visitors center of CERN gives maps to tourists and visitors to find buildings.
The maps have the sites and the building number.

So there are no houses like in a city named "Einstein 23". They are just called 500 for example.
The street names are just there to honor  dead scientists.