Calculate the number 6402

A man and his wife were in a fancy resturant. While ordering, they noticed that the waiter had a spoon in his shirt pocket, and after looking around, they observed the other waiters and busboys each had a similar spoon. So the husband says, "what's with the spoon?"
The waiter said,"well, we had this company come in and evaluate our time management and they found that people drop their spoon 74.8% more often than any other utensil. So if we carry one with us, we can reduce the trips back to the kitchen by 3 hours per shift.
The husband was impressed. Sure enough, he dropped his spoon during dinner and the waiter replaced it with his, stating, "I'll just get another when I go to the kitchen for something else". While ordering dessert, the husband noted that the waiter had a very thin string hanging from the fly of his pants, as did the other waiters, so the husband asks, " hey, there's a string on your pants". The waiter tells him, " not all my customers are as observant as you... the same company found that we can reduce the amount of time spent in the bathroom by 2 hours each shift if we tie a string around the end of you-know-what, and when we have to go we just unzip and pull it out with the string completely eliminating the need to wash up and saving time." The husband was impressed, but asked, " it's a good idea but how do you get it back in your pants?".
The waiter leaned close and whispered, " well I don't know about the rest of them, but personally I use the spoon."