Primes / Is 503 prime?

Is 503 a Prime Number?

Yes

503 is prime: for 503, testing every prime up to √503 ≈ 22.4 (namely 2, 3, 5, 7, 11, 13, 17, 19) finds no divisor. 503 sits between primes 499 and 509, 4 below and 6 above. 503 shares no factor with 2-12; 503's divisors start beyond that range. 503 is odd, digit sum 8 for 503, digital root 8 for 503. 503 has 3 primes within 10 of 503.