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Home >> Numbers >> Perfect Numbers >>

Perfect Numbers

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Definition :-
A given number for which sum of all its factors is equal to it's twice, the number is known as A Perfect Number

Examples 1 = Is given number 6 a prime number ?
Answer = Find the factors of given number 6
Factors of 6 = 1, 2, 3, 6.
Now, add all the above factors.
Sum = 1 + 2 + 3 + 6 = 12
Now, you can calculate that twice of given number 6 = 12
Since the sum of all the factors of 6 is equal to its twice
So, we can say that 6 is a perfect number.

Examples 2 = Is given number 9 a prime number ?
Answer = Find the factors of given number 9.
Factors of 9 = 1, 3, 9.
Now, add all the above factors.
Sum = 1 + 3 + 9 = 13
Now, you can calculate that twice of given number 9 = 18
Since the sum of the factors of 9 is not equal to its twice
Hence, we can say that 9 is not a perfect number.

Examples 3 = Is given number 28 a prime number ?
Answer = Find the factors of given number 28
Factors of 28 = 1, 2, 4, 7, 14, 28.
Now, add all the above factors.
Sum = 1 + 2 + 4 + 7 + 14 + 28 = 56
Now, you can calculate that twice of given number 28 = 56
Since, the sum of all the factors of 28 is equal to its twice
So, we can say that 28 is a perfect number.