The size is 4 bytes for an int.
See DbParameter class on msdn for more info. It is relevant because SqlCeParameter
implements DbParameter
The following section is relevant:
The Size property is used for binary and string types.
For nonstring data types and ANSI string data, the Size property
refers to the number of bytes. For Unicode string data, Size refers to
the number of characters. The count for strings does not include the
terminating character.
For variable-length data types, Size describes the maximum amount of
data to transmit to the server. For example, for a Unicode string
value, Size could be used to limit the amount of data sent to the
server to the first one hundred characters.
See this https://gist.github.com/1932766 for the implementation of the Size property.