Primes / Is 263 prime?

Is 263 a Prime Number?

Yes

263 is prime: for 263, testing every prime up to √263 ≈ 16.2 (namely 2, 3, 5, 7, 11, 13) finds no divisor. 263 sits between primes 257 and 269, 6 below and 6 above. 263 shares no factor with 2-12; 263's divisors start beyond that range. 263 is odd, digit sum 11 for 263, digital root 2 for 263. 263 has 4 primes within 10 of 263.