Coming to density calculation!

If the radius of the neutron has just the critical value of 2x10**-54m (i.e. just a blackhole), the density becomes = 1.67x10**-27kg / ((4/3) 3.14 (2x10**-54m)**3) = 5x10**133 kg/m**3= 5x10**136 g/cc; i.e. a specific gravity of 5x10**136 (so many times heavier than water!).
If any other material cosisting of neutrons, protons, electrons and empty space could become a blackhole for a particular value of radius, the neutron could then be MUCH HEAVIER than as calculated above, especially if the empty space is of orders higher than the dimension of the neutron itself - oops! Now, shall we explore the above 'if', i.e. any other material can become a blackhole?
Let's have a break and meet soon!
srini