198397989 has 6 divisors (see below), whose sum is σ = 286574886. Its totient is φ = 132265320.

The previous prime is 198397987. The next prime is 198398029. The reversal of 198397989 is 989793891.

It can be written as a sum of positive squares in only one way, i.e., 135908964 + 62489025 = 11658^2 + 7905^2 .

It is not a de Polignac number, because 198397989 - 2¹ = 198397987 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198397987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11022102 + ... + 11022119.

It is an arithmetic number, because the mean of its divisors is an integer number (47762481).

Almost surely, 2^198397989 is an apocalyptic number.

It is an amenable number.

198397989 is a deficient number, since it is larger than the sum of its proper divisors (88176897).

198397989 is a wasteful number, since it uses less digits than its factorization.

198397989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22044227 (or 22044224 counting only the distinct ones).

The product of its digits is 8817984, while the sum is 63.

The square root of 198397989 is about 14085.3821034433. The cubic root of 198397989 is about 583.2379237336.

The spelling of 198397989 in words is "one hundred ninety-eight million, three hundred ninety-seven thousand, nine hundred eighty-nine".