PalinPrime

This was a problem posted to reddit from a job application's website. The goal was to find the first 7 digit number from within Pi that was both a prime number and a palindrome. It's a fun little problem, but I cheated a bit by loading a pre-calculated value of Pi into memory first.

// we can use a (relatively) slow algorithm for prime checking because it's only
// checking when a palindrome appears
public static Boolean isPrime(int n)
{
    for (int divisor = 2; divisor <= (Math.Sqrt(n)); divisor++)
    if ((n % divisor) == 0) return false;
    return true;
}
public static int reverse(int n)
{
    int result = 0;
    while ((n / 10) > 0) // break once n has only one digit
    {
        // shift the result one decimal place left, add the last digit from n
        // the result of n % 10 is always the same as the last digit of n
        result = (result * 10) + (n % 10);
        n /= 10;
    }
    result = (result * 10) + (n % 10); // take the final digit
    return result;
}
public static Boolean isPalindrome(int n)
{
    if (reverse(n) == n)
        return true;
    return false;
}