It is possible that it has been removed as it isn't on Fotolia either with that number.
There is two ways you can confirm (that I know of) if the image number is correct.
1: On the comp image it should still have the image number along with the Adobe watermark.
2: if you have the image downloaded and still has the original file name you will see a string of digits in the file name. That string should bring up the proper image in Stock.
Yes, first I just used the number from the file name, but then thinking that I may have accidentally changed the name of the file I typed the image number directly off of the comp image. A few times just to be sure. Any reason why it would be removed?
It was most likely removed by the contributor for any number of reasons.
I would try the contact and support at Fotolia.com and they may be able to track it or at least tell you if indeed the number ever existed possibly. Other than that I can't think of any way to find out.
Have you happened to save it to a CC Library? If so you should be able to get to it through your CC Libraries Web Interface or from any Adobe App that uses Libraries.
Right click on an image in your libraries and select 'Find Similar on Web' and it will take you to similar images on Stock and have that exact image displayed first.