def is_left_truncatable(number):
while number > 0:
if number == 1 or not mrabin.is_prime(number):
return False
tmp = misc.reverse_number(number)
number = misc.reverse_number(tmp // 10)
return True
def add_primes(numbers):
result = []
for number in numbers:
for extra in [1, 3, 7, 9]:
n = number * 10 + extra
if mrabin.is_prime(n):
result.append(n)
return result
