What do you think is the first counterexample to the statement "half of a big number is also a big number"?
Is this the same question as "what's the smallest big number"?
If not, why not?
@christianp If we take as axiomatic the phrase "A billion here, a billion there, pretty soon, you're talking real money." then 2 billion is not real money but 3 billion is. If big numbers are isomorphic to real money, 3 billion would be the smallest big number.
@bencurthoys @christianp I cannot improve on this answer. Brilliant.