Discount at Ichiraku

Ichiraku ramen is a ramen shop in Konoha , it is known for its specialty the pork meat ramen . Lately the sales of the ramen has dropped. So shop owner has came up with a new marketing strategy . He decide to give discount on the ramen through a lucky draw . In this lucky draw a number is selected randomly and the customer has to tell the closest prime number larger than the total number of divis