256.
The first number is the value for 1^1.
The second number is the value for 2^2.
The third number is the value for 3^3.
And the fifth number is the value for 5^5.
So the fourth number must be the value for 4^4, which is 256.
The missing number in the series 1, 4, 27,____, 3125 is?