So when did Narutoverses moon equal are moon on Earth. Last time I checked, the Narutoverse wasn't on Earth. For all we know it could be bigger, or smaller. There is no proof to say otherwise, thus making your calculation invalid.
Also you forget moving objects in space take much less energy then they do on Earth. Not to mention we don't even know how he got the moon into space(if we want to take the legend of how the moon was created seriously). Did he use some technique that defies gravity and pushed it out? If that is the case, he did not "lift" 18 quintillion tons. He just moved an object that weighs that much with a technique that defies weight.
Basically you can assume many things but there is no concrete evidence he lifted the weight.