import math


def is_prime(k: int) -> bool:
    """
    Determine if a number is prime
    >>> is_prime(10)
    False
    >>> is_prime(11)
    True
    """
    if k < 2 or k % 2 == 0:
        return False
    elif k == 2:
        return True
    else:
        for x in range(3, int(math.sqrt(k) + 1), 2):
            if k % x == 0:
                return False
    return True