Adding a prime check function

maths/basic_maths.py

@@ -116,6 +116,35 @@ def euler_phi(n: int) -> int:
     return int(s)
 
 
+def is_prime(n: int) -> bool:
+    """Checks if a number is prime.
+
+    Source: https://en.wikipedia.org/wiki/Prime_number
+
+    >>> is_prime(11)
+    True
+    >>> is_prime(15)
+    False
+    >>> is_prime(1)
+    False
+    >>> is_prime(0)
+    False
+    >>> is_prime(2)
+    True
+    """
+    if n <= 1:
+        return False
+    if n in {2, 3}:
+        return True
+    if n % 2 == 0 or n % 3 == 0:
+        return False
+    for i in range(5, int(math.sqrt(n)) + 1, 6):
+        if n % i == 0 or n % (i + 2) == 0:
+            return False
+
+    return True
+
+
 if __name__ == "__main__":
     import doctest