The numbers are 13 and 41. And you do not need to know that they are prime in order to find the answer. The sum (54) and difference (28) provide all the necessary information.

There are infinitely many expressions that simplify to any particular number; for example: any two numbers which, when added, give 24, any two numbers whose difference is 24, any two numbers whose product is 24, etc.

Actually 2x2x5x7x11 is a prime factorization and on multiplying these numbers we get 1540. Prime factorization of a number is the prime numbers which on multiplying together give that number.