There are 80,658,175,170,943,878,571,660,636,856,403,766,975,289,505,440,883,277,824,000,000,000,000 possible combinations of 52 cards in the deck. This is why the chances of repeating the same combination twice are incredibly low. 

Source: Bright Side: https://brightside.me/wonder-curiosities/14-startling-facts-that-impressed-us-664810/