The answer, according to the Wolfram Alpha site, is 0.288788095086602421278899721929230780088911904840685784114741...
The input I used is:
product(1-1/2^n) from n=1 to infinity
It isn't clear - in this particular page - how this result was obtained.
I assume the question is "What is a half timed by one?" Any numbers, no matter how small or large, when timed by 1 will remain unchanged.
The Moon keeps one side towards the Earth at all times, so the rear side is never seen from Earth. The Moon does wobble back and forth a little bit while doing this so in real life about 59% of the moon is actually visible, just not all at the same time!
the answer is 64,023,737,057,280,000.
1358954496
24
512
If you're on a computer that allows you to ask this question and see the answer, it undoubtedly has a calculator program (in Windows, it's calc.exe). So you can answer this for yourself.
8 times 8 times 8 times 8 times 8 times 8, or 86 is 262,144
4
1 times 1 times 1225
One, and it is STILL the loneliest number...
355687428096000....Literrally there is a button on any good calculator for this it is shown as x! in this case 17! is the above number.