Find the next number in the series below?

6 18 270 72090 ?

5196751830

Next number formed is (number * (number-2)) - number
i.e
(6 * 4) - 6 = 18
(18 * 16) - 18 = 270
(270 * 268) - 270 = 72090
(72090 * 72088) - 72090 = 5196751830