$1, 2, 3, 6, 9, 54$ are some factors of $54$, find the missing factor of $54$. 

Try to find the second perfect number by halving the sum of its factors. It is less than $50$. The third perfect number is between $400 \text{and} 500$. Try to find it.

$25$ has only three factors.

Find out which number has more factors- $24$ or $100$.