There's a lot of sand on this planet. The Sahara Desert is full of it, for one. And then there's the Gobi Desert, and the Kalahari Desert, and all of the other deserts and beaches on coastlines and water's edges all over the world. Every beach you've ever walked on was made up of millions of grains of sand, and if you add all of those grains together, you're looking at trillions - a number so high the brain struggles to deal with it.
Staggeringly, though, there are not as many grains of sand in the world as there are stars in the universe. Scientists have verified over 300 billion stars in the Milky Way alone, and the number for the observable universe - note that isn't the whole universe, just the parts we can currently see - that number becomes 70 billion trillion.