といえば details

Examples

speaking of; that reminds me — N triggers whatever the speaker associates with it

この店みせのラーメンといえば、やっぱり味噌みそだよね。

kono mise no raamen to ieba, yappari miso da yo ne.

Speaking of this shop's ramen, it's gotta be the miso, right. casual

京都きょうとといえば、清水寺きよみずでらが有名ゆうめいです。

kyouto to ieba, kiyomizudera ga yuumei desu.

Speaking of Kyoto, Kiyomizu Temple is famous. neutral

今回こんかいの展示会てんじかいといえば、なんといっても来場者数らいじょうしゃすうの多おおさでしょう。

konkai no tenjikai to ieba, nan to itte mo raijoushasuu no oosa deshou.

Speaking of this exhibition, if anything stands out, it's the sheer number of visitors. formal

The ば here is frozen — と言えば no longer asks a real "if"; it always
launches a fresh topic by whatever the speaker connects with N.

という
と言う packages a clause or name as content and stays open-ended about what happens next; と言えば specifically LAUNCHES a fresh topic by whatever the speaker associates with N, a discourse move plain と言う does not perform on its own.

ば
Same ば-conditional morphology, but frozen — ordinary ば asks a real "if" (言えば "if you say"), while と言えば has drifted into a fixed topic-launcher ("speaking of…") that asks no question at all — reading it compositionally gets the wrong meaning entirely.
と言っても
と言えば free-associates off a topic just mentioned, launching a new related thought (日本[にほん]と言えば、寿司[すし]だね "speaking of Japan, sushi"); と言っても walks back the strength of a claim the speaker just made, introducing nothing new (人気と言っても、一部だけ) — sharing と言 tempts a learner to read one as a register variant of the other, but their functions don't overlap.