199839797 has 2 divisors, whose sum is σ = 199839798. Its totient is φ = 199839796.

The previous prime is 199839779. The next prime is 199839823. The reversal of 199839797 is 797938991.

It is a happy number.

199839797 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

Together with previous prime (199839779) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 137334961 + 62504836 = 11719^2 + 7906^2 .

It is a cyclic number.

It is not a de Polignac number, because 199839797 - 2¹⁰ = 199838773 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199839737) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99919898 + 99919899.

It is an arithmetic number, because the mean of its divisors is an integer number (99919899).

Almost surely, 2^199839797 is an apocalyptic number.

It is an amenable number.

199839797 is a deficient number, since it is larger than the sum of its proper divisors (1).

199839797 is an equidigital number, since it uses as much as digits as its factorization.

199839797 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7715736, while the sum is 62.

The square root of 199839797 is about 14136.4704576496. The cubic root of 199839797 is about 584.6473604612.

The spelling of 199839797 in words is "one hundred ninety-nine million, eight hundred thirty-nine thousand, seven hundred ninety-seven".