What is the significance of the firemen wearing helmets with "F451" on them?

There are two unique symbols of fire in the novel Fahrenheit 451. Though the firemen, who burn books and wear "F451" on their helmets, sybilize destruction. In the future, Bradbury portrays firemen as setting books and knowledge aflame as an order to censor the government. The firemen weare "F451" on their helmets to symbolize what their jobs are. The temperature of 451 degrees is what paper burns at.