Excuse me while I clear out my cranial flatus. I was not forcing the maximum precision. I was using the default. If I add the printf "%25.32" as dvido had I would have gotten slightly different results:
0100001110111101100010001110100001001000001011011111000110101110 - 1.9
1100001110111101100010001110100001001000001011011111000110101110 - 1.9
It would appear that in this case, 1.9041105342991887e+258 is not possible to store. Using all 53 bits of mantissa, I still get about 15.95 digits instead of the 14. Each case will be different and require converting to binary, twiddling the bits, and seeing what you get.