shell script related query

Hi

I have an input to a file. I want the script to return it formatted
the input is a number, say ,
1234567895 and the output should be 21 43 65 87 59 ,ie, the pair of two digits should be reversed.
How can I do this using a shell script?

$ echo 1234567895 | sed 's/\(.\)\(.\)/\2\1 /g'
21 43 65 87 59
$