Primes / Is 409 prime?

Is 409 a Prime Number?

Yes

409 is prime: for 409, testing every prime up to √409 ≈ 20.2 (namely 2, 3, 5, 7, 11, 13, 17, 19) finds no divisor. 409 sits between primes 401 and 419, 8 below and 10 above. 409 shares no factor with 2-12; 409's divisors start beyond that range. 409 is odd, digit sum 13 for 409, digital root 4 for 409. 409 has 3 primes within 10 of 409.