富 is associated with prosperity. Note: 福 (fortune/blessing) is the character hung upside-down on doors during New Year, while 富 appears in names and business signage.
Top 宀 (roof) — the indexing radical, the standard 'under one roof' marker. Anchors 富 as a property-of-the-household word: wealth lives at home. The radical pulls 富 in alongside 家 (home), 安 (peace), 宝 (treasure), 室 (room) — domestic-space characters.
Bottom 畐 supplies the sound (fú → fù, just a tone shift) and a strong semantic echo: 畐 itself depicts a brim-full ceremonial wine jar. House (above) + full jar (below) = a household with full storehouses = wealth. Same phonetic family: 福 (blessing), 副 (secondary), 幅 (width).
