199784197 has 2 divisors, whose sum is σ = 199784198. Its totient is φ = 199784196.

The previous prime is 199784191. The next prime is 199784213. The reversal of 199784197 is 791487991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 141276996 + 58507201 = 11886^2 + 7649^2 .

It is a cyclic number.

It is not a de Polignac number, because 199784197 - 2²⁷ = 65566469 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 (199784191) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99892098 + 99892099.

It is an arithmetic number, because the mean of its divisors is an integer number (99892099).

Almost surely, 2^199784197 is an apocalyptic number.

It is an amenable number.

199784197 is a deficient number, since it is larger than the sum of its proper divisors (1).

199784197 is an equidigital number, since it uses as much as digits as its factorization.

199784197 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1143072, while the sum is 55.

The square root of 199784197 is about 14134.5037762208. The cubic root of 199784197 is about 584.5931346782.

The spelling of 199784197 in words is "one hundred ninety-nine million, seven hundred eighty-four thousand, one hundred ninety-seven".