You need to know the bit depth of each "slice" of your hypercube. (We can't tell you this, but its normally 8 bit for a standard RGB image, but can be as high as 24 or as low as 4, for whatever it is that you're looking at.)
Once you know that:
total_number_of_colours = 2^depth_slice_1 * 2^depth_slice_2 * 2^depth_slice_3 ...
Intensity is a little bit different,
Basic_max_intensity = (2^depth_slice_1 - 1) + (2^depth_slice_2 - 1) + (2^depth_slice_3 - 1) ...
Optical_max = (2^depth_slice_1 - 1)*scale_1 + (2^depth_slice_2 - 1) *scale_2 + (2^depth_slice_3 - 1) * scale_3 ... % Where "scale" is a conversion from pixel values to an optical power or energy.
