199965811 has 2 divisors, whose sum is σ = 199965812. Its totient is φ = 199965810.

The previous prime is 199965769. The next prime is 199965851. The reversal of 199965811 is 118569991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 199965811 - 2²⁷ = 65748083 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (199965851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99982905 + 99982906.

It is an arithmetic number, because the mean of its divisors is an integer number (99982906).

Almost surely, 2^199965811 is an apocalyptic number.

199965811 is a deficient number, since it is larger than the sum of its proper divisors (1).

199965811 is an equidigital number, since it uses as much as digits as its factorization.

199965811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 174960, while the sum is 49.

The square root of 199965811 is about 14140.9268083814. The cubic root of 199965811 is about 584.7702226628.

The spelling of 199965811 in words is "one hundred ninety-nine million, nine hundred sixty-five thousand, eight hundred eleven".