It is just like stupid believing on something like that now in 2016. Lucky number is doesn't exist, it would not make you win something.
If gambling crowd believes in lucky numbers, multipliers or special dance will make you win more - think again.
Just because you first ever win was $21 or something like that doesn't mean that this is your lucky number.
Do yourself a favor and test if that lucky number is that lucky - bet on it every time, see if its really true.