520 is a set of Arabic numerals, not Chinese characters, and there is no distinction between complexity and simplification. Expressed in Chinese characters:

5 writing five (five), traditional is five (five).

2 writing two (two), traditional is two (two).

0 is zero, and traditional is zero.

If 520 is pronounced as 520 (Wu Bai 20), the traditional Chinese character is 520 (Wu Bai 20);

If 520 is pronounced as 520 (520), then the traditional Chinese character is 520 (520).

Extended data:

Whether Arabic numerals (1, 2,3 ...) or so-called Chinese lowercase numerals (1, 2,3 ...) are easy to be altered and tampered with because of their simple strokes. Therefore, the numbers on general documents and commercial financial bills should be capitalized in Chinese characters: one, two, three, four, five, land, seven, eight, nine, ten and hundreds.

In the early years of the Ming Dynasty, Zhu Yuanzhang issued a decree because of a major corruption case at that time, clearly requiring that the number of bookkeeping must be changed from "one, two, three, four, five, six, seven, eight, nine, ten, ten, and one hundred thousand" to "one, two, three, four, five, six, seven, seven, seven.

Baidu Encyclopedia-chinese numerals