I think generally it is two weeks to settle into a cage. The first 2 or 3 days left alone and then after that just occasional spot cleaning, feeding the odd treat through the bars or on the palm of your hand. Of course if he is already quite tame the handling may progress quicker as the others say, but I think the two weeks for settling into a cage and feeling familiar is probably about right. This can be set back as well, if things are moved around in the cage or a big clean is done during that two weeks, which could delay the settling in.
Hammies are all different too - some take a bit longer to build confidence and some are more active and outgoing than others. It's just time and patience
You can test to see if he runs on his wheel at night by putting a small piece of substrate on top and seeing if it's gone in the morning.
Also scatter feeding might tempt him to explore the cage a bit more. But it sounds like he is just building confidence and feels safe in his house
A week isn't very long.
Ironically, if he is quite hand tame and enjoying playtime out of the cage, this could possibly be slowing up his adustment and getting familiar with the environment in the cage. So maybe only get him out if he shows he wants to come out, rather than taking him out every day - for the next week or so. And scatter feed half of his food. I put one half of the usual amount in the food bowl and scatter the other half on the substrate - they like foraging and finding it. Then after a couple of weeks they have got a bit of a routine in the cage - knowing when feeding time is, knowing where everything is and which bits they like to sit in and so on and finding their way around. They scent mark everywhere when it's new so they can find their way around, so if you clean the cage they have to start again with scent marking.