Citigroup's GAAP net income for 3M 2021 was $7.942 bln, up 3.1 times from $2.536 bln in the prior year. 2021 was $7.942 billion, up 3.1 times from $2.536 billion in the previous year. Revenue fell 6.8% to $19.327 billion from $20.731 billion a year earlier.