In reality that answer would depend on the width of your tire, and on how inflated it is. If you're looking for a value to enter into a cyclocomputer, do a roll out instead. But a short answer is that it's about two metres.
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Circumference is equal to the diameter multiplied by pi, or 3,14. Multiply 65 x 3.14.
A 128 inch circumference would imply a radius of 20.4 inches - a regular bicycle wheel, for example.
28" bicycle tires comes in different widths, which affects the circumference together with how hard they're inflated. In actual life even the weight on the wheel will affect the working circumference as tha tire will squash a bit under load. But ignoring all that the circumference is about 2.2 meters.
radius=13 area=40.82 circumfrence=8.28025477707
If its circumference is 21.98 feet then its diameter is 21.98/pi = 7 feet rounded up.