Does IVV, VEA and VWO reinvest their dividends? How do I check if the dividends are distributed or reinvested in the factsheet?

You could check if they have a Dividend Reinvestment Plan (DRIP) option. If not, you will have to manually reinvest the dividends.

Another option is to look for ETFs that are accumulating (acc) where the dividends are automatically reinvested after tax deduction. The ones that pay out the dividends in cash are usually called distributing (dis). You sometimes can see the (acc) or (dist) in the ETF title.

One thing to note is that Singaporeans are subjected to 30% withholding tax on US dividends. So any payout or reinvestment is net of the withholding tax.

There is a Seedly article on investing in Ireland-domiciled ETfs which reduces the withholding tax to 15%. You might want to read that. For searching for such ETFs, you can use the keyword “UCITS” to find one that meets your criteria.