Posted by The long existing BITAND function is now within the documentation, to let you do logical AND on two numbers, and is also available from PL/SQL
If you need other bit operations, a little boolean math should suffice 
Just make sure you stay within the limits of BINARY_INTEGER
CREATE OR replace FUNCTION bitor( x IN binary_integer, y IN binary_integer ) RETURN binary_integer AS
BEGIN
RETURN x - bitand(x,y) + y;
END;
/
CREATE OR replace FUNCTION bitxor( x IN binary_integer, y IN binary_integer ) RETURN binary_integer AS
BEGIN
RETURN bitor(x,y) - bitand(x,y);
END;
/
Learning is not a spectator sport 
It not only long existing, it has been documented since at least Oracle 8.17. https://docs.oracle.com/cd/A87860_01/doc/server.817/a85397/function.htm#98002
And since that version it says in the PLSQL User Guide and Reference “PL/SQL lets you use all the SQL data manipulation, cursor control, and transaction control commands, as well as all the SQL functions, operators, and pseudocolumns.”
… except for the SQL functions that aren’t supported, such as EXTRACT and other XML functions and BIN_TO_NUM, DUMP, MAKE_REF
… and all of the analytic functions (wouldn’t it be great to be able to use these directly in PL/SQL like you can with MULTISET for object types).