I think I got it! The first one is 6436343 (23^5), because W is the 23rd letter, and it is in the fifth place of ARROW. The second one is 59049 (9^5) because I, the 9th letter, is in the 5th place of GOBLIN. The third one is 38416 (14^4) because N, the 14th letter, is in the fourth place of HORNET.