Don't know what your definition of low and high are, but here's the second request:
=IF(ISODD(LEFT(K12,1)),"O","E")&IF(ISODD(MID(K12,2,1)),"O","E")&IF(ISODD(MID(K12,3,1)),"O","E")&IF(ISODD(RIGHT(K12,1)),"O","E")
where K12 contains the number to be evaluated