How is 1337 ironic?

No (that was ironic).

Technically, it in itself does not mean anything, but if you type it into a calculator and turn it upside-down, it says "LEET" as is elite, it is used to refer to someone who is good/skilled at...

I'm not sure...

hey i wanna ask you that do you wanna find the alphabets or letters then: 1=A 3=C 3=C 7=G

1337 speak is when someone type like a "pro", Usually used by nerd'ish gamers and hardcore internet users. this is an example for a 1337 typing:h0w 4r3 u t0d4y m4te0 = o4 = A3 = e7 = tetc...