Is "1Wh4bh" a valid Bitcoin address? The bitcoin address 1Wh4bh looks so short. Is it even a valid address?

If yes, can we send bitcoins to it?
As to elaborate on why this is accepted at all at blockchain.info, 1Wh4bh is:

&gt;&gt;&gt; import base58  
&gt;&gt;&gt; bytes.hex(base58.b58decode('1Wh4bh'))  
'001406e058'


Following https://en.bitcoin.it/wiki/Protocol_documentation#Addresses, it only contains the preface of a bitcoin address ('0x00'), and the checksum: '1406e958'. In fact, the double SHA256 of 0x00 (as the hash160 of the public key is not indicated) is:

1406e05881e299367766d313e26c05564ec91bf721d31726bd6e46e60689539a


The first 4 bytes coincide, so the checksum is right.

Because of this, the bitcoin address could be well formed... in a sense.... I suppose this is the reason why blockchain doesn't reject it.   

But in fact, as no public key is indicated at all because no public key would produce a hash160 equal to the null string, it cannot be used for any purpose.

Note, also, that a null (or less than 160 bits) hashed public key is incorrect even in the case of (all) leading zeros, because Base58Check algorithm used by bitcoin preserves all leading zeroes.