[lisper]

> How do you determine that is from the genesis block?

Go to:

https://blockchain.info/en/address/12c6DSiU4Rq3P4ZxziKxzrL5L...

Scroll down to the bottom, where you will see:

https://blockchain.info/tx/0e3e2357e806b6cdb1f70b54c3a3a17b6...

That is the genesis block.

(Well, OK, that's the transaction contained in the genesis block. The Genesis block itself is https://blockchain.info/block-index/14850)

> Also how do you know it is Sataoshi's?

Because he was the only one mining when bitcoin launched.

[murbul]

The genesis block is actually block 0, you're looking at block 1.

Incidentally, the genesis block reward is unspendable. It's not really known if that was intentional or a bug in the initial implementation, but the rule persists.

[lisper]

Oops, you're right. Here's the genesis block:

https://blockchain.info/block/000000000019d6689c085ae165831e...