Paytm founder Vijay Shekhar Sharma, 39, is the youngest Indian billionaire, while 92-year-old Samprada Singh, chairman emeritus of Alkem Laboratories Ltd, is the oldest, according to Forbes magazine.

Sharma, ranked 1,394th on the list with a fortune of $1.7 billion, is the only Indian billionaire in the under-40 league. Sharma founded fast-rising mobile wallet Paytm in 2011. He has also created Paytm Mall, an e-commerce business business and Paytm Payments Bank.

“One of the biggest beneficiaries of India’s demonetisation, Paytm has notched up 250 million registered users and 7 million transactions daily. Sharma owns 16% of Paytm, which is now valued at $9.4 billion,” Forbes said.

Of the 2,208 billionaires in Forbes’ 2018 list of the world’s richest, just 63 are under the age of 40 and more than half (34) are self-made entrepreneurs. In all, the 63 youngest billionaires in the world are worth a collective $265 billion, up from $208 billion last year.

Meanwhile, 92-year-old Samprada Singh, who is the chairman emeritus of Alkem Laboratories, is the oldest Indian billionaire. He was ranked 1,867th on the list with a net worth of $1.2 billion. Singh founded the pharma firm Alkem Laboratories 45 years ago. Singh worked in a chemist’s store before venturing out on his own distributing pharmaceuticals.