what's the error in my isbn checker?

Question

import java.util.Scanner;

// declare variables

public class ISBNChecker {
public static void main(String [] args) {
    Scanner keyboard = new Scanner(System.in);
    System.out.println("Please enter a 13 digit book number:");
    String book = keyboard.nextLine(); 
    int isbn = Integer.parseInt(book);

//check length of isbn number

    if (book.length() != 13) {
        System.out.println("ILLEGAL ISBN NUMBER");
    }

//check if number multiple every 1,3,5,7,9,11,and 13th number is multipled by 3 and every other number by one, then add them together

    for(int i = 0; i < book.length(); i++){
        char c = book.charAt(i); //get the current char
        int value = c - '0'; //subtract '0' from the char
        isbn += value * (i+1);

//the rest is to see if total of isbn is dividable by 10 to have no remains

    }
    if ((isbn % 10) != 0) {
        System.out.println("Illegal ISBN number");
    } else {
        System.out.println("It's an ISBN number");
    }
}

}

//the problem with this code is that it won't work and I am pretty sure I messed up the format. Please help me check. 
// when I process it. this error shows up :

Exception in thread "main" java.lang.NumberFormatException: For input string: "1234567898765"
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
    at java.lang.Integer.parseInt(Integer.java:583)
    at java.lang.Integer.parseInt(Integer.java:615)
    at ISBNChecker.main(ISBNChecker.java:8)

Answer 1

That number is too big to fit into an Integer. Try using Long instead..

Max Integer is 2147483647.

Max Long is 9223372036854775807L.