Now, if I'm correct it's 3600.000 coins per day.
Mining actually pays out a bit more than that, closer to 3625, due to transaction fees. Also, that's an average during times when the total hashing power in the network isn't increasing. During those times of constant hash power, there will be some days that are a bit higher, and some that are a bit lower.
In times of increasing total network hash power, the number is more likely to be higher than that. In times of decreasing total network hash power, the number is more likely to be lower than that.
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If only 1 person is mining then he will receive the full amount, if 10 persons are mining then it gets split among them depending on their contribution to solving the blocks (hashrate).
Not exactly, but approximately. First it depends on if they are mining in a pool or not. If they are, then the portion of the daily bitcoins that they receive depends on the rules of the mining pool they've chosen to work with as well as how lucky the pool is (how many blocks they manage to mine in a day). If they are solo-mining, then it is possible for them to have lucky days where they solve more blocks than their percentage of the total hash power indicates. It is also possible for them to have unlucky days where they solve less blocks than their percentage of the total hash power indicates. Over a long period of time this variation will balance out and trend towards their average daily revenue being approximately equivalent to the their contribution to solving the blocks.