The amount showed that he had been living a “Spartan lifestyle”, his spokesman Garba Shehu said.
Mr Buhari has five homes and two mud houses, as well as farms, he added.
The former military ruler was elected in March largely on a promise to tackle corruption and insecurity.
Corruption is endemic in Africa’s biggest economy and last month, Mr Buhari said that $150bn (£100bn) was missing from state coffers.
Mr Shehu said in a statement that Mr Buhari also has an orchard and a ranch with 270 head of cattle, 25 sheep, five horses and a variety of birds.
He also held shares in three firms – Berger Paints, Union Bank and Skye Bank, the statement added.
However, Nigeria’s Vice-President Yemi Osinbajo is richer than his boss.
The statement said Mr Osinbajo has $1.4m (£900,000) in his bank accounts.
In his declaration of assets, Mr Osinbajo also revealed that he owned a four-bedroom residence, a three-bedroom flat, a two-bedroom flat and a two-bedroom mortgaged property in Bedford, UK.
The statement did not give the value of all the assets held by the president and the vice-president, saying the documents submitted to the Code of Conduct Bureau would be made public as soon as the vetting process was completed.BBC