263 (number)

263 (two hundred [and] sixty-three) is the natural number between 262 and 264. It is also a honaker prime number.

In mathematics

263 is the smallest prime number in base 10 whose expansion in any smaller base is never prime when interpreted in base 10:

It is also:

• a balanced prime,
• an irregular prime,
• a Ramanujan prime,
• a Chen prime, and
• a safe prime.

It is also a strictly non-palindromic number and a happy number.

References