SQL & PL/SQL

Hi Gurus,

I am bit poor at math and yes i know bitand is used for binary and operation. But i can't figure out this conversion.

Here is a flag column values from ts$

 flags   0x40 = COMPRESS 
         0x10000 = OLTP Compression 
         0x20000 = Columnar Low Compression
         0x40000 = Columnar High Compression
         0x80000 = Archive Compression

And here is corrosponding conversion in dba_tablespaces script.

case when bitand(ts.flags,  65536) = 65536  then 'OLTP'
                  when bitand(ts.flags, (131072+262144)) = 131072
                    then 'QUERY LOW'
                  when bitand(ts.flags, (131072+262144)) = 262144
                    then 'QUERY HIGH'
                  when bitand(ts.flags, (131072+262144)) = (131072+262144)
                    then 'ARCHIVE LOW'
                  when bitand(ts.flags, 524288) = 524288
                    then 'ARCHIVE HIGH'
                  else 'BASIC' end))

Now, here are my question

1. 0x40 & 0x10000 and othere are hexa values Right ?
2. So what does 65536 means here all other values are multiple (131072) are of this
3. So, what are we checking here with this kind of bitand(ts.flags, (131072+262144)) thing

Can someone please explain in simple terms. I searched manuals and other but they give just high level information but not basic.