According to the author of the book of 2 Chronicles, King Solomon received a lot of gold and silver not only from traders and business people, but also from the leaders of nearby countries. This made Solomon very rich and powerful because everyone brought him treasures.
2 Chronicles 9:14: Beside [that which] chapmen and merchants brought. And all the kings of Arabia and governors of the country brought gold and silver to Solomon. [governors: or, captains]
This verse states the same amount of gold received by Solomon yearly as 666 talents, aligning rather than contradicting with 2 Chronicles 9:14.
1 Kings 10:14: Now the weight of gold that came to Solomon in one year was six hundred threescore and six talents of gold,