I am thinking of a positive integer.
It is three larger than a prime number.
Sum of its digits equal to 11.
Sum of its divisors is equal to 120.
What is the positive integer?
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Say the mystery number is n .
Since n is 3 more than a prime (and that prime is clearly not 2 ), n must be even.
Since n is a divisor of itself, and the sum of its divisors is 1 2 0 , we must have n < 1 2 0 .
There are only four even numbers less than 1 2 0 with digit sum 1 1 : 3 8 , 5 6 , 7 4 , 9 2
It's easy to check that, of these, only 5 6 has the correct divisor sum.