user30956: Now, the height of the blockchain is 485531. How much hash power is ideally required to mine block number 500000.
And how much hash rate does a node require to publish a block successfully each hour?

user51948: Firstly, new blocks are published every 10 minutes on average, not every hour. 
There is no 'required' amount of hash power to mine a block. It is all a game of luck, a race against the rest of the network. To mine a valid block roughly once per hour, you would be mining a sixth of the total blocks (~6 blocks mined per hour), so in theory you would need around a sixth of the total hashpower on the bitcoin network. You can see the current network hash rate here:
https://blockchain.info/charts/hash-rate
At the time of this post, that's roughly 1.4 exahashes per second (million terahashes per second).

30956: <p>Now, the height of the blockchain is 485531. How much hash power is ideally required to mine block number 500000.</p>

<p>And how much hash rate does a node require to publish a block successfully each hour?</p>
 51948: <p>Firstly, new blocks are published every 10 minutes on average, not every hour. </p>

<p>There is no 'required' amount of hash power to mine a block. It is all a game of luck, a race against the rest of the network. To mine a valid block roughly once per hour, you would be mining a sixth of the total blocks (~6 blocks mined per hour), so in theory you would need around a sixth of the total hashpower on the bitcoin network. You can see the current network hash rate here:
<a href="https://blockchain.info/charts/hash-rate" rel="nofollow noreferrer">https://blockchain.info/charts/hash-rate</a></p>

<p>At the time of this post, that's roughly 1.4 exahashes per second (million terahashes per second).</p>
