What is Bitcoin's "genesis hash"?
They're exactly the same number; one is written in little endian notation and the other is big endian.  Notice that the bytes (two-hex-digit pairs) are exactly reversed from one to the other.

Block explorers like blockchain.info usually expect big-endian for block hashes.  The proof-of-work requirement means that the most significant bits have to be zero, so big endian makes it easier to see this.