DAS BASU RULE 1

For any known PRIME number greater than 10 and less than infinity , adding the digits of the number will make the sum to be
1/2/4/5/7/8

NOTE : This rule NOT applicable for proving a number as prime but it is used to verify a PRIME number


Example:  1601(prime)
                1+6+0+1 = 8


                25(not prime)
                2+5 = 7