Additive primes: Difference between revisions

=={{header|Python}}==

<lang Python>def is_prime(n: int) -> bool:

if n <= 3:

return n > 1

if n % 2 == 0 or n % 3 == 0:

return False

i = 5

while i ** 2 <= n:

if n % i == 0 or n % (i + 2) == 0:

return False

i += 6

return True

def digit_sum(n: int) -> int:

sum = 0

while n > 0:

sum += n % 10

n //= 10

return sum

def main() -> None:

additive_primes = 0

for i in range(2, 500):

if is_prime(i) and is_prime(digit_sum(i)):

additive_primes += 1

print(i, end=" ")

print(f"\nFound {additive_primes} additive primes less than 500")

if __name__ == "__main__":

main()</lang>

{{out}}

<pre>2 3 5 7 11 23 29 41 43 47 61 67 83 89 101 113 131 137 139 151 157 173 179 191 193 197 199 223 227 229 241 263 269 281 283 311 313 317 331 337 353 359 373 379 397 401 409 421 443 449 461 463 467 487

Found 54 additive primes less than 500</pre>