Is it possible to add/update Document Library fields like Content Type, Version, File Size,..?
These fields are visible in view mode.
ContentType and File Size is a Calclated field. So we can't change that. And the Version is a Number Field Type and this is ReadOnly.
We can change the Content Type by updating ContentTypeId field with the ContentType ID in that list. To update Version field, we have to set the readonly property to false and then update the verion nuber (not recommended). We can't update the File Size field, because it automatically update the value to the field, whenever the document is added or modified.