A standard analog clock typically has 12 numbers on its face, representing the hours from 1 to 12. This is the most functionally correct answer as these numbers mark the hours of the day. However, if considering every individual digit displayed (for example, 10, 11, and 12 have two digits each), the count comes to 15 digits in total. This interpretation counts each separate symbol on the clock face rather than the hour numbers as a whole. A straightforward answer is that there are 12 numbers on a clock, but the riddle-like alternative answer is 15 digits if counting each digit individually on the clock face.