Check prime number or not in constant time(without using any loop) | MATLAB

Code:

clc

clear all

close all

x=input('Enter the number:');

if(x==2 || x==3)

    disp('Prime number');

elseif(rem((x-1),6)==0 || rem((x+1),6)==0)

    disp('Prime number');

else

    disp('Not a prime number');

end