W.A. Mozart wrote 27 concertos for Piano and Orchestra.
23
Mozart performed a great many of his works himself.
He wrote 25 in a major key and only 2 in a minor key.
He did not write the following types of concertos: viola, double bass, oboe, flute, clarinet, harp, and many more instruments. The only concertos that he has written are: Bassoon Concerto, Piano Concerto, Violin Concerto, Cello Concerto.
Joseph Haydn composed more than 200 principal compositions. Most notable of them are his 84 string quartets and 104 symphonies. Haydn composed more than 30 piano sonatas and oratorios.
3 complete concertos, and two movements of another.
2
Only considering attested works, the number is 44 with the following distribution: piano (27), violin (5), horn (4), flute (1), bassoon (1), harp and flute (1), oboe (1), clarinet (1) for a total of 41 to which we can add 3 more: 1 sinfonian concertante for violin and viola 1 sinfonia concertante for oboe, clarinet, horn and bassoon 1 flute concerto (arrangement of bassoon concerto)
Beethoven composed 32 piano sonatas, 5 piano concertos, completed 9 symphonies, one opera, and he was known for many other orchestral works. These included chamber music and overtures such as The Creatures of Prometheus, Coriolan Overture, Egmont, King Stephen and Zur Namensfeier.
Schubert wrote a fiendishly difficult fantasy for piano and orchestra, the Wanderer Fantasy, based on the theme from his song, Der Wanderer. He did not write a formal concerto for any instrument.
Wolfgang Amadeus Mozart wrote many Piano Sonatas, Concertos, Duets, Trios, etc. There are probably anywhere between 200-300 piano pieces written by Mozart.