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

Yes

The spelling and meaning of "dezenove" are identical in both Brazilian and Continental Portuguese. The only difference lies in pronunciation:

• Brazilian Portuguese: The final "e" is typically pronounced as a clear, unstressed "i" (/de.ze.ˈno.vi/).
• Continental Portuguese: The final "e" is a very closed, unstressed vowel, often sounding nearly silent or like a very short, muffled /ɨ/.

Brazilian Portuguese Examples

1. Eu tenho dezenove anos. (I am nineteen years old.)
2. O ônibus chega às dezenove horas. (The bus arrives at 19:00.)
3. Tem dezenove pessoas na festa. (There are nineteen people at the party.)
4. Ele comprou dezenove livros. (He bought nineteen books.)
5. O preço é dezenove reais. (The price is nineteen reais.)

Continental Portuguese Examples

1. Eu tenho dezenove anos. (I am nineteen years old.)
2. O autocarro chega às dezenove horas. (The bus arrives at 19:00.)
3. Há dezenove pessoas na festa. (There are nineteen people at the party.)
4. Ele comprou dezenove livros. (He bought nineteen books.)
5. O preço é dezenove euros. (The price is nineteen euros.)