Question

A ______ is a number in which the sum of all its factors is twice the number

Answer 1

Answer:

it is called perfect no.

Step-by-step explanation:

for example,

factors of 28 is 1,2,4,7,14 and28

and it's sum =1+2+4+7+14+28

= 56

=2×28

hence the no. is 28

and 28 is a perfect no.