Mary Trump's book about the president has sold more copies than his did in 29 years

Mary Trump's tell-all book about the president and his family has sold more copies in a week than his Art of the Deal did in 29 years.

People bought an estimated 1.35 million copies of Too Much But Never Enough: How My Family Created the World's Most Dangerous Man in its first week according to publisher Simon & Schuster, while 1.1 million copies of The Art of the Deal sold between its publication in 1987 and Trump's presidency in 2016.

In a statement, Simon & Schuster CEO Jonathan Karp said:

Mary Trump’s memoir has transcended the usual ceiling for political books to reach a larger audience of people who want to read stories about unusual families. 

We knew Too Much and Never Enough would make news and offer fascinating psychological insights into the president, but we’re moved to see how deeply the book has touched readers, and thrilled to have people compare the book to The Godfather.

The 1.35 million sales figure includes pre-orders, print books, ebooks and audiobooks.

The book debuted at #1 on bestsellers lists in the UK, Ireland, the US and Canada.

Shocking allegations made by the president's niece in the book include claims that Trump paid someone else to sit the SAT exams that helped him win a place at the University of Pennsylvania and that he went to see a movie while his brother died in hospital.

Mary Trump, a psychologist, also claimed that her uncle is a 'narcissist', writing in her book's prologue:

I have no problem calling Donald a narcissist – he meets all nine criteria as outlined in the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).

The criteria includes traits such as "a grandiose sense of self-importance" and "a need for excessive admiration".

In response to the book, which he initially tried to block, Trump called his niece "a mess" who "knows little about me".

Meanwhile, Trump's ghostwriter, Tony Schwartz, who helped write The Art of the Deal, has spoken of his "deep remorse" for helping to advance Trump's career.

In 2016, he told The New Yorkerthat if he were to work on the book again he would name it 'The Sociopath'.

I put lipstick on a pig. I feel a deep sense of remorse that I contributed to presenting Trump in a way that brought him wider attention and made him more appealing than he is.

The Art of The Deal is part-memoir and part business how-to and helped to make Trump a "household name" in the 1980s.

But books decrying Trump are now all the rage.

Ahead of his November re-election bid, Trump's former national security advisor John Bolton and Washington Post reporters Philip Rucker and Carol Leonnig have also offered us insider glimpses at Trump's chaotic presidency so far this year.