This service is lacking a major feature and too complicated! Almost half of the time, I need to know if a number is even. Why doesn't it provide an end point

This service is lacking a major feature and too complicated! Almost half of the time, I need to know if a number is even. Why doesn't it provide an end point for that?! Don't even tell me about the 409 status code. Am I suppose to know it's an even number when it returns an odd number to me? I only recognize status code 200, all other are errors, don't make this so complicated!