>>> from prime import improved_is_prime

>>> improved_is_prime(1)
False
>>> improved_is_prime(2)
True
>>> improved_is_prime(53)
True
>>> improved_is_prime(63)
False
>>> improved_is_prime(71)
True
>>> improved_is_prime(84)
False
>>> improved_is_prime(97)
True
>>> improved_is_prime(125)
False