Python Min Perimeter Rectangle
def min_perimeter_rectangle(n: int) -> int:
    i = 1
    min_perimeter = float("inf")
    while i * i < n:
        if n % i == 0:
            min_perimeter = min(min_perimeter, 2 * (i + n // i))
        i += 1

    return int(min_perimeter)

This searches factor pairs up to the square root and picks the pair with the smallest perimeter.