A "Neighbors of a Number" bet in roulette involves betting on a specific number and the two numbers on either side of it on the roulette wheel, covering five numbers in total. For instance, if a player chooses the number 17, a neighbors bet would cover the numbers 2, 25, 17, 34, and 6. This bet allows players to spread their wager across a small section of the wheel, increasing their chances of winning if the ball lands near the chosen number. It is commonly used in European and French roulette, where players can easily place these types of call bets.