Police Brigadier General Andre Dizon, the Philippine National Police director of the Bicol Region, said 20 died in Bicol, the region southeast of Manila, which bore the brunt of the storm.
The National Disaster Risk Reduction and Management Council (NDRRMC) tallied one death in another region south of the capital. The Office of Civil Defense said one died in the northern Philippines.
The NDRRMC said the storm affected over 2 million people in at least 12 regions across the country.
The numbers, including the death toll, could rise as the police and other agencies continue to assess the typhoon's impact. As of Thursday, some towns and villages remain isolated.
Flash floods and landslides hit several regions in the Philippines on Tuesday, as Trami brought heavy rains and left many areas without power.
As of Thursday, the agency said 256 roads and 40 bridges nationwide remain not passable. Power has yet to be restored in at least nine regions.
The agency said two airports and 86 seaports remained closed.
The slow-moving Trami, spotted over the Cordillera Administrative Region in northern Luzon on Thursday morning, packs 95 km per hour winds and gusts of up to 160 km per hour as a "severe" tropical storm. Trami hit land early in the morning on Thursday.
The state weather bureau forecasts that Trami will cross northern Luzon over the next 12 hours. It is expected to blow away from the Philippines on Friday afternoon.
Trami is the 11th typhoon this year to hit the Philippines, which is lashed by an average of 20 typhoons yearly.
MNA/