How can you help my program better?

Given an int see if its characters were from smallest to largest and return true or false, you could only take an if, without strings, or ternary operator, or cycles: * ME COULD ME SAY HOW TO IMPROVE MY CODE KNOWING WHAT I SAID

private boolean funcion(int numero) {
    int modulo = Math.abs(number % 10);
    number = number / 10;
    if (modulo > (number % 10)) {
        return funcion(number);
    }
    return (number == 0) ? true : false;
}