[Lapha]

Hindi and other Indo-Aryan languages are incredibly irregular, but when laid out on a chart it doesn't seem as daunting of a task as the initial prospect of learning 100 numerals for 0-100 would be. For example, if you know 22 is 'bais' and you know the tens place for thirty is 'tis' and sixty is 'sath' you can probably figure out what 'battis' and 'basath' are, although if you know 29 is 'untis' you won't be able to figure out what 'unsath' is from the examples provided in this post.

Irregularity isn't too uncommon though, just not to the same degree. Many Germanic languages have special words for eleven and twelve, with remnants of vigesimal are common throughout Europe. French and Danish were mentioned previously, with Danish having exceptions on top of that system. 23 being '3 and 20th' or 67 being '7 and 3 score' which makes sense, but 34 '3 and 30' and 45 '4 and 5 10s' breaking the rule, and numbers like 78 '8 and 3 score and half fourth score' really stretching the limits. The Celtic languages still use vigesimal and Breton at least has similar degrees of irregularity as Danish. Japanese numerals are also a mess, but that mostly stems from the differences in readings.

There's probably many more examples, but these are the ones that I can think of off the top of my head. The one notable exception being the Pirahã language, which has words for 'one' 'two' and 'many' and that's about it.

https://en.wikipedia.org/wiki/Hindustani_numerals

https://en.wikipedia.org/wiki/Danish_language#Numerals

https://en.wikipedia.org/wiki/Japanese_numerals