Declension table of ?avyathatva

Neuter	Singular	Dual	Plural
Nominative	avyathatvam	avyathatve	avyathatvāni
Vocative	avyathatva	avyathatve	avyathatvāni
Accusative	avyathatvam	avyathatve	avyathatvāni
Instrumental	avyathatvena	avyathatvābhyām	avyathatvaiḥ
Dative	avyathatvāya	avyathatvābhyām	avyathatvebhyaḥ
Ablative	avyathatvāt	avyathatvābhyām	avyathatvebhyaḥ
Genitive	avyathatvasya	avyathatvayoḥ	avyathatvānām
Locative	avyathatve	avyathatvayoḥ	avyathatveṣu

Compound avyathatva -

Adverb -avyathatvam -avyathatvāt