Suppose there is integer m so thatThen since 123457=(1)(123457), Those factors m-n and m+n could be 1 and 123457 respectively. We have the system m = 1+n Substitute in m+n = 123457 1+n + n = 123457 2n+1 = 123457 2n = 123456 n = 61728 m = 1+n = 61729 So n2 + 123457 = 617282 + 123457 = 617282 + 123457 = 627192, which is a perfect square. Edwin