Every Culture is characterised by a numerical symbolism which differs from that region to the other regions. The reason is usually cultural and religious traditions and legends passed down through times but are still present in the society and are perceived to as having some lucky and unlucky powers.
For example, In China, 8 and 9 are lucky while 4 and 7 are unlucky, In US, UK, France and Netherlands, 7 is lucky and 13 is unlucky.
Here are more such places and the reason why these numbers are perceived that way.