The square numbers it could be 1 more than are
9,16,25,36,49,64,81,100,121,144
Add 1 to each: 10,17,26,37,50,65,82,101,122,145
The only primes in that list are 17, 37, and 101, so it's one of those three.
The sums of digits of those are 8, 10, and 2
10 is the only sum of digits which is a multiple of 5.
So the answer is 37.
Edwin