Which number is better, 399, 388 or 369?

369。

369 is an auspicious number, 3 stands for life, which means I hope this person will live well, be healthy and healthy, 6 stands for smoothness, and 9 stands for longevity. 369 means to hope that the other person will live a healthy life and everything will be smooth and long-lasting.

388 (for "getting rich") 399 (for "lasting").