45² = 2025
20 + 25 = 45

45³ = 91125
9 + 11 + 25 = 45

45⁴ = 4100625
4 + 10 + 06 + 25 = 45

45⁵ = 184528125
18 + 4 + 5 + 2 + 8 + 1 + 2 + 5 = 45

45⁶ = 8303765625
8 + 3 + 0 + 3 + 7 + 6 + 5 + 6 + 2 + 5 = 45

(Thanks, Dheeraj.)