| Name | NGC 3921 |
| Type | GX [S0-a] |
| Other names | PGC37063 / UGC6823 |
| Constellation | Ursa major |
| descr | VV misprints dec as +56d21.5; corrected in MCG errata. |
| RA | 11:51:06.8 |
| Dec | +55:04:46.0 |
| major_axis | 2.1' |
| minor_axis | 78.0'' |
| position_angle | 20.0 |
| mag | 12.4 |
| surface_bright | 13.2 |