The longest written novel of all time was more than 500,000 words long and was published through a regular, mainstream publisher. The novel is called "Artamène ou le Grand Cyrus" and it was originally published in 1649–54. It comes in ten parts. Each of the parts makes up three volumes. It is usually attributed to Madeleine de Scudéry. There are specific considerations that are taken into account when compiling a longest novel award. Some count pages while others count words or characters. Word count is the most accurate.
The font and spacing plays a big role too. The length of the book, like page count, can denote its actual size but the thickest novel isn't necessarily the longest one. The again, what language it is written in plays a part too. It is difficult to really determine the longest novel but for all things considered, this one is although there are others with honorable mention that follow close behind.