I have had literally thousands of them, but I tend to only keep the ones that I would actually use for my phone (I have used the same in the laptop for the last 5 years and I don't plan on changing it). I only have like 100 right now, but because, as I said, those are the ones I like most right now, and constantly change my background and whatsapp background with those 100. When I get tired of some, I delete them, and I am constantly downloading more, so that number is aprox. the same always.
I'll dump some of my favorites.