Here's some Java software for handling big numbers. You can view the javadoc or download the source code from github.
This software was developed at LinkedIn, for sorting big numbers and storing them in a database. To learn more about that application, see the LinkedIn blog.
The source code is licensed under the Apache License, Version 2.0. Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.