28
There is no one-digit number that is equal to both 14 and 28.
42 - 28 = 14
14³ - 28 = 2716
54 - 28 = 26
Silicon 28 (28Si) has 14 protons, neutrons and electrons.
14 is less than 28 or 14 < 28
14 is less than 28 or 14 < 28
28
14 + 14 = 28
A number is perfect if all it's factors (barring itself) sum to make the original number. In this case, the factors of 28 are 1,2,4,7 and 14. Added up, these equal 28. Thus, 28 is a perfect number.
14