161

161 = 7 x 23.

161 is a divisor of 22² - 1.

161 is a hexagonal pyramidal number.

161 is a Cullen number.

Every number greater than 161 is the sum of distinct primes of the form 6n - 1.

161 is the smallest semiprime that yields a palindromic prime (191) when turned upside down.

161 is the sum of five consecutive prime numbers: 161 = 23 + 29 + 31 + 37 + 41.

There are 161 ways to bet on a roulette wheel.

Source: Prime Curios!