Full Idea
To give spatial co-ordinates for the number four makes no sense; but the only conclusion to be drawn from that is, that 4 is not a spatial object, not that it is not an object at all. Not every object has a place.
Gist of Idea
Not all objects are spatial; 4 can still be an object, despite lacking spatial co-ordinates
Source
Gottlob Frege (Grundlagen der Arithmetik (Foundations) [1884], §61)
Book Reference
Frege,Gottlob: 'The Foundations of Arithmetic (Austin)', ed/tr. Austin,J.L. [Blackwell 1980], p.72
A Reaction
This is the modern philosophical concept of an 'object', though I find such talk very peculiar. It sounds like extreme Platonism, though this is usually denied. This is how logicians seem to see the world.