Declension table of ?saptatha

Neuter	Singular	Dual	Plural
Nominative	saptatham	saptathe	saptathāni
Vocative	saptatha	saptathe	saptathāni
Accusative	saptatham	saptathe	saptathāni
Instrumental	saptathena	saptathābhyām	saptathaiḥ
Dative	saptathāya	saptathābhyām	saptathebhyaḥ
Ablative	saptathāt	saptathābhyām	saptathebhyaḥ
Genitive	saptathasya	saptathayoḥ	saptathānām
Locative	saptathe	saptathayoḥ	saptatheṣu

Compound saptatha -

Adverb -saptatham -saptathāt