What set does 789 belong to?

Answer 1

To any set that contains it!

It belongs to {789},

or {789, sqrt(2), pi, -3/7},

or {789, bananas, France, cold}

or all whole numbers between -43 and 5003,

or multiples of 3,

or composite numbers,

or counting numbers,

or integers,

or rational numbers,

or real numbers,

or complex numbers,

etc.