Four numbers have been given, out of which three are alike in some manner and one is different. Select the number that is different.

8276 7286 6394 5378

6394

8276   ⇒ 8 + 2 + 7 + 6 = 23 7286  ⇒ 7 + 2 + 8 + 6 = 23 6394  ⇒ 6 + 3 + 9 + 4 = 22 5378  ⇒ 5 + 3 + 7 + 8 = 23