Full Idea
There is the tantalizing possibility that perhaps mathematical objects 'have no nature' at all, beyond their 'structural role'.
Gist of Idea
Maybe mathematical objects only have structural roles, and no intrinsic nature
Source
Geoffrey Hellman (Structuralism [2007], §1)
Book Reference
'Oxf Handbk of Philosophy of Maths and Logic', ed/tr. Shapiro,Stewart [OUP 2007], p.537
A Reaction
This would fit with a number being a function rather than an object. We are interested in what cars do, not the bolts that hold them together? But the ontology of mathematics is quite separate from how you do mathematics.