203

203 = 7 x 29.

203 is the sixth Bell number.

203² + 203⁰ + 203³ is a prime number.

The square of 203 is one of three squares that use the same digits: 148² = 21904, 203² = 41209, and 302² = 91204.

203 is 21112 in base 3, 535 in base 6, and 313 in base 8.

The telephone area code 203 covers the southwestern part of Connecticut.

Source: Prime Curios!