Due to the leading zeros I guess there is a missing decimal point, either after or before the first zero: 0.0065 = 6.5 × 10^-3 .00065 = 0.00065 = 6.5 × 10^-4
It is sixty five hundred thousandths.
0.0065 = 6.5 x 10^-3
You divide by 1,000. So, .65 milliseconds equals .00065 seconds.