def reverse_bits(x):
    """
    Question 5.3: Reverse the bits in a number
    """
    MAX_LEN = 64
    bin_str = '{:08b}'.format(x)
    remaining = MAX_LEN - len(bin_str)
    full_str = bin_str[::-1] + ('0' * remaining)
    return int(full_str, 2)