Not sure where that math came from. 16 bit 8 by 8 pixel image would be 16^(8x8) or in Python...

  print(f"{16 ** (8*8):.4E}")

  1.1579E+77

EDIT: I calculated 16 color, not 16 bit. Disregard

Python wanted to use a float to convert to exponential format but it overflowed. Need to use strings ;-)

  n=(2**16)**(8*8); s=str(n); print(s[0] + '.' + s[1:6] + 'E+' + str(len(s) - 1))

  1.79769E+308