When in doubt, remember the infinite monkey theorem: If you spin the dial enough times, you will eventually hit the right number.
The puzzle is designed to make you laugh at yourself. While you are calculating prime numbers, the answer is usually the silliest thing in the room. Look for a crayon drawing of a banana, look for the number of fingers on a statue, or simply input 0000 . monkey business safe combination
Seriously. If there is a bunch of bananas, count the brown spots. Count the bananas in the bunch. Count the bites taken out of an apple. Monkeys = Food. The combination is often the quantity of fruit or the Fibonacci sequence hidden in a fruit bowl. When in doubt, remember the infinite monkey theorem: