Which number is closest to the number of ways one can arrange a deck of 52 playing cards in a different order?

I had no idea a number could be called "quintillion" in America but "trillion"in Europe

Am often in awe of these probability facts, but often wonder ‘how on earth has anyone worked that one out?’ … so thank you for explanation.

Someone has a whole lotta time musing.lol!

Player #53553731, I like SNAP

Player #53553731, mine too!!

wow!! a little bit complicated, but, I think, I got it!!