What is wrong with this code? It take forever to run. Thanks.

public class Print_Primes {

public static void main(String args){

```
int count = 4;
String prime = "2,3,5,7,";
int number = 10;
int divisor;
boolean state = true;
while(count < 51){
for (divisor = 2; divisor <= (int)(Math.sqrt(number)); ++divisor){
if(number % divisor == 0){
state = false;
break;
}
}
if (state == true){
prime += number + ".";
++count;
}
++number;
}
System.out.println(prime);
}
```

}