Their late father, Oei Wie Gwan, acquired a bankrupt cigarette company in 1950, and later renamed it Djarum after the needle of a gramophone.
With his brother, he also owns popular electronics brand Polytron, prime real estate in Jakarta and a stake in gaming startup Razer.
Hartono, who long advocated to get the game of bridge included in the Asian Games, won a bronze medal with five teammates in 2018.
Michael "Bambang" Hartono and his brother R. Budi are among the richest in Indonesia.
The brothers get the bulk of their fortune from their investment in Bank Central Asia.
The Hartonos bought the stake in BCA after another wealthy family, the Salims, lost control of the bank during the 1997-1998 Asian economic crisis.
The family first got rich in tobacco and is still one of the biggest clove cigarette makers in the nation.
In what was Indonesia's second-largest IPO of 2022, the brothers listed Global Digital Niaga, which owns e-commerce giant Blibli, raising $510 million.