** Number class Reference can have any of these objects.
| Name | Type | Parent | Since | Detail |
| AtomicInteger | Class | java.lang.Number | 1.5 | Link |
| AtomicLong | Class | java.lang.Number | 1.5 | Link |
| Byte | Class | java.lang.Number | 1.1 | Link |
| Double | Class | java.lang.Number | 1.0 | Link |
| DoubleAccumulator | Class | java.lang.Number | 1.8 | Link |
| DoubleAdder | Class | java.lang.Number | 1.8 | Link |
| Float | Class | java.lang.Number | 1.0 | Link |
| Integer | Class | java.lang.Number | 1.0 | Link |
| Long | Class | java.lang.Number | 1.0 | Link |
| LongAccumulator | Class | java.lang.Number | 1.8 | Link |
| LongAdder | Class | java.lang.Number | 1.8 | Link |
| Number | Class | java.lang.Object | 1.0 | Link |
| NumberFormatException | Class | java.lang.IllegalArgumentException | 1.0 | Link |
| Short | Class | java.lang.Number | 1.1 | Link |