This episode count allowed director Tetsurō Araki and screenwriter Toshiki Inoue to adapt the manga faithfully without the need for "filler" episodes—unrelated side stories used to allow the manga source material to progress. Consequently, the 37 episodes form a continuous, uninterrupted narrative chain where almost every scene contributes to the plot’s advancement.
Here’s a proper review of the query (Spanish for "How many episodes does Death Note have?" ): cuantos capitulos tiene death note