Subtracting from 16811 its reverse (11861), we obtain a triangular number (4950 = T99).
It is a happy number.
It is a strong prime.
It is a cyclic number.
It is a Sophie Germain prime.
It is a self number, because there is not a number n which added to its sum of digits gives 16811.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 16811.
It is a good prime.
216811 is an apocalyptic number.
16811 is an equidigital number, since it uses as much as digits as its factorization.
16811 is an odious number, because the sum of its binary digits is odd.
The square root of 16811 is about 129.6572404457. The cubic root of 16811 is about 25.6171719099.
The spelling of 16811 in words is "sixteen thousand, eight hundred eleven".