199898591 has 2 divisors, whose sum is σ = 199898592. Its totient is φ = 199898590.

The previous prime is 199898581. The next prime is 199898599. The reversal of 199898591 is 195898991.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199898591 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 199898591.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199898599) 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, 99949295 + 99949296.

It is an arithmetic number, because the mean of its divisors is an integer number (99949296).

Almost surely, 2^199898591 is an apocalyptic number.

199898591 is a deficient number, since it is larger than the sum of its proper divisors (1).

199898591 is an equidigital number, since it uses as much as digits as its factorization.

199898591 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2099520, while the sum is 59.

The square root of 199898591 is about 14138.5498195536. The cubic root of 199898591 is about 584.7046903607.

The spelling of 199898591 in words is "one hundred ninety-nine million, eight hundred ninety-eight thousand, five hundred ninety-one".