Authors, and especially new authors, often worry about the length of their novel, which is usually gauged one of two ways: by the number of words, or the number of pages. The former is the standard measure for a manuscript, as it is more accurate; the page count of a book can be manipulated by the design of the interior (i.e., the size of the page, type, margins, line spacing and leading, and the addition of decorative elements).
In general, a first novel for adult readers should be somewhere between 75,000 and 110,000 words in length. If the novel is much shorter than this, publishers (and readers) will feel cheated—no amount of design can hide the fact they a book is very thin on content. On the other hand, a first novel that gets much above 110,000 words often suggests that the author is overwriting, or is unable to edit their own work. Consider trimming your manuscript and saving the material for another book.
Of course these are broad generalizations, but first-time authors (and many established authors) are wise to consider them before shopping a manuscript. Discipline, craft, and market expectations each play a part in the commercial and artistic success of novel.