| Factorisation | 3 × 23 × 31 |
| Prime | no |
| Binary | 100001011011 |
| Hexadecimal | 0x85B |
| Bit length | 12 |
| Digit sum | 15 |
| Digits spoken | two one three nine |
2139 opens the sequence 2139847, beginning at digit 1 of seven.
2139 falls below the cardinality of a PubMed record, a Canadian patent application, a European patent application. Those systems assign identifiers sequentially, so it necessarily holds one in each. This is a property of the registries, not of the number. The cardinalities are published here.