#C , <del>20</del>, 29 bytes

    #include<byteswap.h>
    bswap_32

[Try it online!][1]


  [1]: https://tio.run/##HcvbCoJAFIXh@3kKMQwHNMe954jhkwSho5ZQk3ggIurVbexiwc8Hy6YXa9d11zt7W5r2WL/mdnpWw@FaZlm9FcJ6r3oXO/ruHmNcfCdbuS4OoyZM9o4WdBh7N2@wBGkZRMvJhYlL/t8zgv/R4rMykhMOJAftJ7nm6EVqLYwAohiXHhQQVCgMaCEM4YwZhRo48wlSYK7RKxhupAIjfg