1- You may not know that 2520 is the smallest digit, which is divided by all the digits from 1 to 10.

2- If you multiply the above equation with your age, your age will be written three times in the result.

3- If 23 men are locked in a room, there is a 50% probability that the birthdays of two of them will take place on the same day.

4- If you multiply 21978 by 4, you will get the answer 87912, which is the opposite of that number.