What does it mean?

[cnbtcnews]

Not yet redeemed
 
1.62864268
 
18KPtjWa3pdat3DDWZVu3XJLNvevrtrTrN
 
Address
 

OP_DUP OP_HASH160 50437a1ee16dd83204f64a76a70dc2b1bbba476f OP_EQUALVERIFY OP_CHECKSIG

I swear I haven't send 1.62864268BTC to such address with my client.

[meanig]

That looks like change from the transaction which the client sent back to you i.e. you own the address 18KPtjWa3pdat3DDWZVu3XJLNvevrtrTrN