198888989 has 8 divisors (see below), whose sum is σ = 221574360. Its totient is φ = 177258816.

The previous prime is 198888973. The next prime is 198888997. The reversal of 198888989 is 989888891.

It can be written as a sum of positive squares in 4 ways, for example, as 2748964 + 196140025 = 1658^2 + 14005^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 198888989 - 2⁴ = 198888973 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198888589) 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 in 7 ways as a sum of consecutive naturals, for example, 263402 + ... + 264155.

It is an arithmetic number, because the mean of its divisors is an integer number (27696795).

Almost surely, 2^198888989 is an apocalyptic number.

It is an amenable number.

198888989 is a deficient number, since it is larger than the sum of its proper divisors (22685371).

198888989 is a wasteful number, since it uses less digits than its factorization.

198888989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 527599.

The product of its digits is 23887872, while the sum is 68.

The square root of 198888989 is about 14102.8007502056. The cubic root of 198888989 is about 583.7186643365.

The spelling of 198888989 in words is "one hundred ninety-eight million, eight hundred eighty-eight thousand, nine hundred eighty-nine".