Complete the series: 1, 4, 9, 16, _____?

Complete the series: 1, 4, 9, 16, _____?

Explanation

The given series is a square of natural number

(1)^2 = 1

(2)^2 = 4

(3)^2 =9

(4)^2 = 16

(5)^2 = 25