INTEGER should work. This should be documented better on the SQL reference page. I see the types documented in the PARAMETERS section but not in the CAST description.

Here are the other types

    BIGINT
    BINARY
    BIT
    CHAR
    DECIMAL
    DOUBLE
    FLOAT
    LONGVARBINARY
    LONGVARCHAR
    NUMERIC
    REAL
    SMALLINT,
    DATE
    TIME
    TIMESTAMP
    TINYINT
    VARBINARY
    VARCHAR