if you are gone 10 hours a day- it might be nice to get him a friend.
If having another cat is doable in your living situation, I think 2 is a nice number.
There are so many kitties needing homes. Maybe you could try a rescue organization that will allow you to bring home a kitty for a trial period to see which one gets along best with your cat. Depending on your cat, he may be happier with grown male or prefer a kitten female.

My male cat to this day is jealous of the girl kitten I adopted after I had him for 7 months- they've been together for 4+ years now and still do not cuddle together. But I've heard of other cats becoming instant best friends with new cats introduced to their household, so who knows?

Cats are really good at keeping themselves occupied when their humans are gone. I am home quite a bit and half the time my cat is busy doing other things. She loves to play fetch so we have regular playtimes during the day. If you can have another kitty that might be an option. You have to take into account your kitties age, personality, and temperament when considering anothe kitty. Just make sure that when you are home with your kitty that you spend quality time with him and he knows you love him.

I started having two cats at a time back when I was living alone. I mean, my long work days (sometimes 16 hrs) with no one else there, definitely meant whatever lone cat I had would be awfully lonely. If your cat does have company for some of the time when you are gone, then it may not be as necessary as it was for my cats.

So he's got company for at least part of the day. And he's got excellent cat-TV with the birds. It's possible that a couple more ways of enriching the environment might make things even better - like leaving a radio or tv on so there will be voices and music to keep him company (ooooh, if you've got cable, you could leave the tv on Animal Planet, wouldn't that be fun?), and rotating his stock of toys so he doesn't get bored with them. There are toys that hang from door knobs, plus a nice kitty climbing tree is always great (but I've made some really fun kitty playgrounds with some big boxes glued together, holes cut to different levels so they could climb around, different toys left inside, some apholstery material attached to one side for skritching and climbing).

After that, it's a question of your kitty's personal preferences. I've had cats that were happier as only cats, and ones I know I couldn't meet all their social needs by myself so they needed a co-cat.

I feel the best answer to a bored kitty is another kitty. ;)

Some times I think she does. I think it depends on the kitty themselves, with the various personalities they have. There are nights i'm greeted at the door and some that i'm not, because she is off sleeping.

The trial new kitty idea is good, I know the shelter i adopted hannah does give an option, that if for any reason it doesn't workout you bring them back to them and not some other shelter or home. I think I would schedule a week off if you bring another kitty home, to help adjust and see if it fits. Also lots of questions of the prospective kitty and social skills with others, where and how they were found etc.

I have two cats. They play all the time but sleep all day. I've come home sick and seen them laying stretched out in my bed under the covers. However, when I come home at my normal time, they are waiting for me by the door.. and I come in.. my youngest runs around yapping about god knows what ahahhaha

My youngest pretty much doesn't shut up. Usually, when he's sleeping he's quiet ahahhaha ;) To answer your question, two would be good.. but it may not solve the problem. He's a ball of energy. Ahahahha