Joining String with function in IF()?

A B
1 $100 =IF(NOT(ISBLANK(A1)), "Deposited on" + NOW())

Can I join a string like "Deposited on" with a function like above? I wanted to make it auto update on the date when I key in $100.

Why does =IF(NOT(ISBLANK(A1)),NOW()) shows 38563.68864? I can't get the date out.Pls help