Multitudinous as an adjective is existing in great numbers; innumerable or myriad while Innumerable as an adjective is not capable of being counted, enumerated, or numbered, hence, indefinitely numerous; of great number.
Part of speech: adjective
Definition: existing in great numbers; innumerable or myriad crowded with many people
Part of speech: adjective
Definition: Not capable of being counted, enumerated, or numbered, hence, indefinitely numerous; of great number.
We hope you now know whether to use Multitudinous or Innumerable in your sentence.