Laxey Wheel Isabella was celebrated by the people of Laxey with a grand fayre on Saturday 24 September 2004. It is currently maintained by Manx National Heritage as part of the Great Laxey Wheel & Mines Trail. The wheel features today on the reverse side of the £20 notes issued by the Isle of Man Government. A water-powered wheel was used because the Isle of Man does not have a supply of coal for a steam-powered pump. Water from the surrounding area – including a number of local springs and streams – is collected in a cistern, which is above the level
Largest known prime number the progression of the largest known prime number in ascending order. Here M = 2 − 1 is the Mersenne number with exponent "n". The longest record-holder known was M = 524,287, which was the largest known prime for 144 years. No records are known before 1456. GIMPS found the fourteen latest records (all of them Mersenne primes) on ordinary computers operated by participants around the world. A list of the 5,000 largest known primes is maintained by Chris K. Caldwell, of which the twenty largest are listed below. Largest known prime number The largest known prime number () is