Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
sixty-fourth is a noun and adjective meaning "one part in sixty-four equal parts". It carries 2 recorded senses.
one part in sixty-four equal parts
the ordinal number of sixty-four in counting order
Definitions, synonyms and semantic relations for sixty-fourth come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.