Family wealth and a surge in entrepreneurs, especially those who founded technology startups, has led to a spate of younger billionaires globally.

The youngest billionaire is only 21 years old, according to data compiled by Forbes. Many are self-made, but nearly all of them are men. While there are a total of 2,153 billionaires, now there are a whopping 71 people who are under the age of 40 based on the 2019 Forbes list.

Here are the top 20 youngest billionaires and their net worth, listed by age.

The Youngest Billionaires in the World: The Top 20

1. Kylie Jenner

Kylie Jenner, 21, is the founder of Kylie Cosmetics and a self-made U.S. billionaire.

She is worth $1 billion and owns a 100% stake in her cosmetics company, Kylie Cosmetics and lives in Hidden Hills, Calif.

2. Alexandra Andresen

Alexandra Andresen, 23, inherited 42% of Ferd, her family's investment company. Her sister, Katharina Andresen, also inherited an equal stake.

She is worth $1.4 billion and lives in Oslo.

3. Katharina Andresen

Katharina Andresen, 23, also inherited 42% of Ferd, her family's investment company like her sister, Alexandra Andresen.

She is worth $1.4 billion and lives in Oslo.

4. Gustav Magnar Witzoe

Gustav Magnar Witzoe, 28, has about a 50% stake in Salmar ASA, one of the largest salmon producers in the world. The stake was given to him by his father, Gustav Witzoe, the founder of the company.

He is worth $3 billion and lives in Kverva, Norway.

5. Evan Spiegel

Evan Spiegel, 28, is the founder of Snapchat (SNAP) , a social media company.

He is worth $2.1 billion and lives in Los Angeles.

6. John Collison

John Collison, 28, is co-founder of Stripe, a payments company.

He is worth $2.1 billion and lives in San Francisco.

7. Ludwig Theodor Braun

Ludwig Theodor Braun, 29, has a 10% stake in B. Braun Melsungen, a medical device company.

He is worth $1 billion and lives in Melsungen, Germany.

8. Anna Kasprzak

Anna Kasprzak, 29, owns shares in ECCO, a Danish shoe maker with her family members, her mother, Hanni, and her brother, Andre.

She is worth $1 billion and lives in Haderslev, Denmark.

9. Jonathan Kwok

Jonathan Kwok, 30, and his brother Geoffrey Kwok, run Empire Group Holdings, a property developer in Hong Kong. The brothers also inherited their father's stake in Sun Hung Kai Properties.

He is worth $2.3 billion and lives in Hong Kong.

10. Patrick Collison

Patrick Collison, 30, is co-founder of Stripe, a payments company.

He is worth $2.1 billion and lives in San Francisco.

11. Bobby Murphy

Bobby Murphy, 31, is a co-founder of Snapchat, a social media company.

He is worth $2.1 billion and lives in Venice, Calif.

12. Said Gutseriev

Said Gutseriev, 31, has stakes in several coal, oil, retail and financial companies that he received from his father, Mikhail Gutseriev. He is also the CEO of Forteinvest, an oil refinery and a company that is part Safmar Group, his father's company.

He is worth $1.3 billion and lives in Moscow.

13. Lukas Walton

Lukas Walton, 32, received one-third of the estate of John Walton, his father, when he died. He is the grandson of Sam Walton, the founder of Walmart (WMT) . Lukas Walton also owns stakes in Arvest Bank and First Solar (FSLR) .

He is worth $17.8 billion and lives in Jackson, Wyoming.

14. Eva Maria Braun-Luedicke

Eva Maria Braun-Luedicke, 32, has a 12% stake in B. Braun Melsungen, a medical device company.

She is worth $1.2 billion and lives in Melsungen, Germany.

15. André Kasprzak

André Kasprzak, 32, owns shares in ECCO, a Danish shoe maker with his family members, his mother, Hanni, and his sister, Anna.

He is worth $1 billion and is a citizen of Denmark. 

16. Christopher Kwok

Christopher Kwok, 33, and his brother, Jonathan Kwok, run Empire Group Holdings, a property developer in Hong Kong. The brothers also inherited from their father, Walter, a stake in Sun Hung Kai Properties. He is the executive director of Sun Hung Kai Properties.

He is worth $1.8 billion and lives in Hong Kong.

17. Jihan Wu

Jihan Wu, 33, is the cofounder and co-CEO of Bitmain Technologies, a Chinese mining-chip behemoth.

He is worth $1.5 billion and lives in Beijing.

18. Aiyawatt Srivaddhanaprabha

Aiyawatt Srivaddhanaprabha, 34, is CEO of King Power, an airport duty-free empire in Thailand. He inherited the company after his father, Vichai Srivaddhanaprabha, died. The estate of his father is shared with his mother and three siblings.

He is worth $1 billion and lives in Bangkok, Thailand.

19. Geoffrey Kwok

Geoffrey Kwok, 34, is the oldest son of Walter Kwok, former chairman of Sun Hung Kai Properties a Hong Kong developer. He inherited a stake in the company from his father.

He is worth 2.9 billion and lives in Hong Kong.

20. Julio Mario Santo Domingo, III

Julio Mario Santo Domingo, III, 34, owns a stake in Anheuser-Busch InBev (BUD) . He inherited his grandfather's stake in SABMiller. The two beer giants merged in 2016.

He is worth $1.7 billion and lives in New York City.

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