199959887 has 2 divisors, whose sum is σ = 199959888. Its totient is φ = 199959886.

The previous prime is 199959883. The next prime is 199959917. The reversal of 199959887 is 788959991.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 199959887 - 2² = 199959883 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 (199959883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99979943 + 99979944.

It is an arithmetic number, because the mean of its divisors is an integer number (99979944).

Almost surely, 2^199959887 is an apocalyptic number.

199959887 is a deficient number, since it is larger than the sum of its proper divisors (1).

199959887 is an equidigital number, since it uses as much as digits as its factorization.

199959887 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 14696640, while the sum is 65.

The square root of 199959887 is about 14140.7173438974. The cubic root of 199959887 is about 584.7644479873.

The spelling of 199959887 in words is "one hundred ninety-nine million, nine hundred fifty-nine thousand, eight hundred eighty-seven".