Question 719489
we try the first digit as 9 because it is a perfect square and the greatest 3-digit numbers have 9 in their thousands place

the last one is not prime, so the middle number must be the prime so we choose 7 (greatest prime less than 9)

6 is not a prime, it is our only last digit possible if we require our number to not be a multiple of 3

so our number is 976