Quote Originally Posted by impulse View Post
Девяносто двухнедельный, Девяносто двухлетний , Девяносто двухгодовалый are all good words to know. Thanks

But why it is dative case?
It is required by the sentence: Ему стало одиноко. - (it) became lonely TO HIM. It is an impersonal structure due to the verb "стать". Other examples:

Мне холодно.
Тебе жарко.
Ему смешно.
Ей интересно.
Мне стало плохо.
Тебе стало хорошо.
etc.

All of those sentences do not have any grammatical subject. It is like some condition occurs "to someone".

BTW, all the adjective you quoted are written as a single word (without spaces), and the first part comes in genitive:

девяностадвухнедельный, девяностадвухлетний
other examples:
двадцатипятиэтажный дом
сорокасемилетний мужчина
пятидесятитрёхстраничный рассказ
сташестидесятисемитомный роман

So, you put the whole number into genitive, add a noun, form an adjective from it, and spell everything without spaces. It is the right way to use those combinations as adjectives.