I think it is this...repeating:
0.647 058 823 529 411 764 705 882 352 941 176 470 588 235 294 117
Here is the answer I got on an online 'really big number calculator' : (as you can see it repeats itself after 16 sets of 3 digits)
0.647 058 823 529 411 764 705 882 352 941 176 470 588 235 294 117 647 058 823 529 411 764 705 882 352 941 176 470 588 235 294 117 647 058 823 529 411 764 705 882 352 941 176 470 588 235 294 117 647 058 823 529 411 764 705 882 352 941 176 470 588 235 294 117 647 058 823 529 411 764 705 882 352 941 176 470 588 235 294 117 647 058 823 529 411 764 705 882 352 941 176 470 588 235 294 117 647 058 823 529 411 764 705 882 352 941 176 470 588 235 294 117 647 058 823 529 411 764 705 882 352 941 176 470 588 235 294 117 647 058 823 529 411 764 705 882 352 941 176 470 588 235 294 117 647 058 823 529 411 764 705 882 352 941 176 470 588 235 294 117 647 058 823 529 411 764 71
I take that back.....it does repeat after 16 digits ....you are correct!