def test_case_97():
"""test_case_97."""
assert divisors(97) == '97 is prime'
def test_case_15():
"""test_case_15."""
assert divisors(15) == [3, 5]
def test_case_13():
"""test_case_13."""
assert divisors(13) == '13 is prime'
def test_case_12():
"""test_case_12."""
assert divisors(12) == [2, 3, 4, 6]
def test_a_medium_number():
assert divisors(253) == [11, 23]
def test_a_small_number():
assert divisors(15) == [3, 5]
def test_a_prime_number():
assert divisors(13) == '13 is prime'