Lab4 Sum of Prime number

void setup() {
  size(350, 100);
  background(0);
  int max_val = 10;
  int p_num =2;
  int sum=0;
  while (p_num <= max_val) {
    if (prime_number(p_num)) {
      sum += p_num;
      println(sum);
    }
    p_num++;
  }
  textSize(18);
  textAlign(CENTER);
  text("Sum of Prime number from 1 to "+max_val, width/2, height/2-20);
  text("'"+sum+"'", width/2, height/2+20);
}

boolean prime_number(int p_num) {
  boolean result = true;
  int divisor = 2;
  while (divisor<p_num) {
    if (p_num%divisor==0) {
      result = false;
      break;
    }
    result = true;
    divisor++;
  }
  return result;
}