28. The sum of its factors (smaller than 28) is 1 + 2 + 4 + 7 + 14 = 28.
27.5
25 is a perfect square occurring between 20 and 30.
The two perfect numbers between 1 and 30 are: 6, 28
-20
29
It is: 3030
perfect square numbers are 16 and 25
25 is a perfect square occurring between 20 and 30.
28 is a perfect number.
The only prime number between 25 and 30 is 29.
The only prime number between 25 and 30 is 29.
The number is 28.
The only square number between 20 and 30 is 25.
1, 4, 9, 16, 25
1, 4, 9, 16, 25.
36
It is: 29
29