> With IEEE FP numbers, the product of the smallest and biggest non-null non-infinite numbers is no longer approximately 1, but it is approximately 4.

This is just wrong? The largest Float64 is 1.7976931348623157e308 and the smallest is 5.0e-324 They multiply to ~1e-16.

>the smallest is 5.0e-324

That's a subnormal [1]. The smallest normal double is 2.22507e-308:

  DBL_MIN          = 2.22507e-308
  DBL_TRUE_MIN     = 4.94066e-324