Just a heads up to those of you still on 500px. The Chinese company that bought them has a record of stealing and licensing images without permission. It took the intervention of the government to deal with this issue. https://techcrunch.com/2019/04/11/vcg-black-hole-image/
I used them for a number of early years when the site was at its best but haven’t been active for a few years since it turned into another Instagram “lets all clone each others’ work” site. I kept my images and account up though because of the visibility on google search. I recently found an image of mine from the site being used without permission so I manually deleted everything and have submitted a ticket for deletion of my account. Apparently, they’re pretty backed up with account deletion requests.