*_000_0000_0000_****_****_****_****_****_****_****_****_****_****_****_****_**** 
    => 2^53 = 9,007,199,254,740,992
    => #infinities = 2
    => #NaNs= 9,007,199,254,740,990
        => #signalling = 4,503,599,627,370,495
        => #quiet      = 4,503,599,627,370,495