221 (number)
# 221 (number)

221 (two hundred [and] twenty-one) is the natural number following 220 and preceding 222.

## In mathematics

Its factorization as 13 × 17 makes 221 the product of two consecutive prime numbers, the sixth smallest such product.

221 is a centered square number.

## In other fields

In Texas hold 'em, the probability of being dealt pocket aces (the strongest possible outcome in the initial deal of two cards per player) is 1/221.

Sherlock Holmes's home address: 221B Baker Street.

