I checked out About Disk Utility and noticed the (606) version number. I've spent some time trying to figure out what it signifies and whether or not anyone else has the same version number. I did the same when the version numbers for a few applications on my MacBook Air (mid-2011) had similar symmetry, but that was a while ago so I don't remember what I had learned--I do remember a (404) as well.
Is (606) normal/OK?
rMB 1.3 (2015) 512GB
Is (606) normal/OK?
rMB 1.3 (2015) 512GB