BigInteger is small for my number

I have working with really big number in java. I'm using BigInteger. My number in hex is 0xffffffff00000001000000000000000000000000ffffffffffffffffffffffff

It is about this in decimal: 1.1579208921035625e+77

The code:

public class BigNumber
{
    public static void main(String[] args)
    {
        BigInteger fp = new BigInteger(0xffffffff00000001000000000000000000000000ffffffffffffffffffffffff);
    }
}

And I get error:

BigNumber.java:5: error: integer number too large: ffffffff00000001000000000000000000000000ffffffffffffffffffffffff
        BigInteger fp = new BigInteger(0xffffffff00000001000000000000000000000000ffffffffffffffffffffffff);

How can I use this big number without loosing the data? Is this possible ? I thought that BigInteger is only limited by memory.