199997867 has 2 divisors, whose sum is σ = 199997868. Its totient is φ = 199997866.

The previous prime is 199997851. The next prime is 199997869. The reversal of 199997867 is 768799991.

It is a strong prime.

It is an emirp because it is prime and its reverse (768799991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 199997867 - 2⁴ = 199997851 is a prime.

Together with 199997869, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (199997869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99998933 + 99998934.

It is an arithmetic number, because the mean of its divisors is an integer number (99998934).

Almost surely, 2^199997867 is an apocalyptic number.

199997867 is a deficient number, since it is larger than the sum of its proper divisors (1).

199997867 is an equidigital number, since it uses as much as digits as its factorization.

199997867 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 15431472, while the sum is 65.

The square root of 199997867 is about 14142.0602105917. The cubic root of 199997867 is about 584.8014686586.

The spelling of 199997867 in words is "one hundred ninety-nine million, nine hundred ninety-seven thousand, eight hundred sixty-seven".