* Nano (n) = 10^-9 (one billionth)

* Milli (m) = 10^-3 (one thousandth)

Conversion:

* 5 million nanometers = 5,000,000 nm

* 5,000,000 nm * (1 m / 1,000,000,000 nm) = 0.005 m

* 0.005 m * (1000 mm / 1 m) = 5 mm

Answer:

5 million nanometers is equal to 5 millimeters.