The 8th prime number, one of the 4th pair of twin prime numbers (17, 19), the 8th prime number, the 7th wagstaff prime number, one of the prime number combinations (n, n+2, n+6, n+8), (1 1,/. The next combination is (10 1, 103, 107, 109) the fourth central triangle number, the third central hexagon number, the third octahedron number and the seventh mersenne prime exponential cycle unit/kloc-. 6543838+01111is a prime number. The sum of every positive integer is at most the power of 19 (Waring problem) Keith number.