19800811 has 2 divisors, whose sum is σ = 19800812. Its totient is φ = 19800810.

The previous prime is 19800799. The next prime is 19800817. The reversal of 19800811 is 11800891.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 19800811 - 2¹⁵ = 19768043 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 19800811.

It is not a weakly prime, because it can be changed into another prime (19800817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9900405 + 9900406.

It is an arithmetic number, because the mean of its divisors is an integer number (9900406).

Almost surely, 2^19800811 is an apocalyptic number.

19800811 is a deficient number, since it is larger than the sum of its proper divisors (1).

19800811 is an equidigital number, since it uses as much as digits as its factorization.

19800811 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 28.

The square root of 19800811 is about 4449.8102206723. The cubic root of 19800811 is about 270.5376165025.

The spelling of 19800811 in words is "nineteen million, eight hundred thousand, eight hundred eleven".