Did some quick math, and if my info is close 250 billion usd using 590 Euro notes would be somewhere between about 400-600 tons (depending on the exchange rate).

1.21g - weight of 500 euro note

2.1 - pounds per kg

((((250,000,000,000 / 500) * 1.21) / 1000) * 2.1) / 2000 * exchangerate

Swiss francs were also used, but this should at least give us an order of magnitude.