Primes / Is 67 prime?

Is 67 a Prime Number?

Yes

67 is prime: for 67, testing every prime up to √67 ≈ 8.2 (namely 2, 3, 5, 7) finds no divisor. 67 sits between primes 61 and 71, 6 below and 4 above. 67 shares no factor with 2-12; 67's divisors start beyond that range. 67 is odd, digit sum 13 for 67, digital root 4 for 67. 67 has 5 primes within 10 of 67.