Numbers are just an abstraction for physical properties. Aliens with no contact with earth will have no idea what our Arabic numerals mean, they won't recognize a 3 or a 7 as being numbers. But they will surely know what 3 means, as a trio, that it is one and one and one.

When we get into things that have units, like the speed of light for instance, things get a little muddy because we have no concise and effective way to define our units to an outside perspective. Sure, c may be equal to around 300 million meters per second, but what is a meter and what is a second to someone who has no reference to either? It's at this point that I think math becomes more of a reflection of ourselves. We define things in units and with relations to other objects and other units because we have that frame of reference, and by defining those units and using them in relation to other maths we've created this grand interconnecting web of mathematical axioms and theories and proofs and units that all refer to four other theories and axioms and units in their own definitions. But at the base of that web holding it all together are numerals. Two is two no matter what it is two of, and that is an illustration of physical properties of the universe irrespective of units or home culture. Two is two is two even if it's called dos or İki or दो.

I would argue that we, humanity, do not invent math any more than we invented gravity or atomic weights. We merely discover principles and relations between principles and define them to the best of our understanding.