Is the word muitos the same in Brazilian and European Portuguese?

Yes

The word "muitos" is identical in meaning, grammar, and spelling in both Brazilian and Continental Portuguese. The only differences lie in pronunciation:

• Pronunciation of the "s": In Continental Portuguese (Portugal), the "s" at the end of words is almost always pronounced as a "sh" sound ([ʃ]), so "muitos" sounds like mwee-toosh. In Brazil, the pronunciation of the final "s" varies by region; in many places (like São Paulo), it is a soft "s" sound ([s]), while in others (like Rio de Janeiro), it may also be a "sh" sound.
• Vowel quality: Brazilian Portuguese tends to have more open, musical vowels, whereas Continental Portuguese often uses more closed or reduced vowels, making the word sound slightly "sharper" or more clipped in Portugal.

Brazilian Portuguese Usage

1. Tem muitos alunos aqui. (There are many students here.)
2. Eu vi muitos filmes legais. (I saw many cool movies.)
3. Tem muitos ônibus na rua. (There are many buses on the street.)
4. Eu tenho muitos celulares. (I have many cellphones.)
5. Eu comi muitos doces. (I ate many sweets.)

Continental Portuguese Usage

1. Há muitos alunos aqui. (There are many students here.)
2. Eu vi muitos filmes giros. (I saw many cool movies.)
3. Há muitos autocarros na rua. (There are many buses on the street.)
4. Eu tenho muitos telemóveis. (I have many mobile phones.)
5. Eu comi muitos rebuçados. (I ate many candies.)