Generally, people graduated from high school in China recognizes over 3000 Chinese characters(han zi) I did a little research through Baidu, and it is said that you can be easily understand over 92% informations in all Chinese books(of course modern Chinese literature) if you memorize 1000 Han zi. Percentage goes up to 98% after you master 2000 han zi, and 3000 means you can figure out over 99% Chinese books. This is for your reference only

More than 90000

the question about symbols is misleading don't learn separate symbols, learn words words from HSK exam lists

about 50000 but for a normal chinese, 2000 - 3000 is totally enough. for a normal life in china, 800 - 1000 is enough.

In China, which uses simplified Chinese characters, the Xiàndài Hànyǔ Chángyòng Zìbiǎo (现代汉语常用字表, Chart of Common Characters of Modern Chinese) lists 2,500 common characters and 1,000 less-than-common characters, while the Xiàndài Hànyǔ Tōngyòng Zìbiǎo (现代汉语通用字表, Chart of Generally Utilized Characters of Modern Chinese) lists 7,000 characters, including the 3,500 characters already listed above. GB2312, an early version of the national encoding standard used in the People's Republic of China, has 6,763 code points. GB18030, the modern, mandatory standard, has a much higher number. The New Hànyǔ Shuǐpíng Kǎoshì (汉语水平考试, Chinese Proficiency Test) proficiency test covers approximately 2,600 characters in its highest level (level six). In the Republic of China (Taiwan), which uses traditional Chinese characters, the Ministry of Education's Chángyòng Guózì Biāozhǔn Zìtǐ Biǎo (常用國字標準字體表, Chart of Standard Forms of Common National Characters) lists 4,808 characters; the Cì Chángyòng Guózì Biāozhǔn Zìtǐ Biǎo (次常用國字標準字體表, Chart of Standard Forms of Less-Than-Common National Characters) lists another 6,341 characters. The Chinese Standard Interchange Code (CNS11643)—the official national encoding standard—supports 48,027 characters, while the most widely used encoding scheme, BIG-5, supports only 13,053. In Hong Kong, which uses traditional Chinese characters, the Education and Manpower Bureau's Soengjung Zi Zijing Biu (常用字字形表), intended for use in elementary and junior secondary education, lists a total of 4,759 characters.