Exception in thread "main" java.lang.NumberFormatException: For input string: "1.0"
<p>I'm writing a Java program to do some computation on big prime numbers, I get this error:</p>

<p><code>Exception in thread "main" java.lang.NumberFormatException: For input string: "1.0"
    at java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
    at java.lang.Integer.parseInt(Integer.java:492)
    at java.math.BigInteger.&lt;init&gt;(BigInteger.java:338)
    at java.math.BigInteger.&lt;init&gt;(BigInteger.java:476)
    at Solution.sumOfDivisorsModulo(Solution.java:24)
    at Solution.main(Solution.java:49)</code></p>

<pre><code>public static BigInteger sumOfDivisorsModulo(BigInteger n){
    BigInteger sum = (n.add(one)).mod( MODULO);
    for (BigInteger test = n.subtract(one); test.compareTo(new BigInteger(Double.toString(Math.sqrt(n.longValue())))) &gt;= 0; test.subtract(one))
    {
            if(n.mod(test).compareTo(zero) == 0)
            {
                    sum = sum.add(test);
                    sum = sum.add(n.divide(test));
                    sum = sum.mod(MODULO);
            }
    }
    return sum;
}

public static void main(String[] args) {
        int m = 2;
        int a = 0;
        primeList = new BigInteger[m];
        fillList(m); // fills the list primeList with prime number up to the mth
        BigInteger n = new BigInteger("1");
        for (int i = 0; i &lt; m; i++){
                n.multiply(primeList[i].pow(a+i));
        }
        System.out.println(sumOfDivisorsModulo(n).toString()); // base10
}
</code></pre>

<p><code>one</code> and <code>zero</code> are variables defined as <code>BigInteger("0")</code> and <code>BigInteger("1")</code>.
Can you help me figure out what the problem is? I thank you in advance.</p>