198905643 has 12 divisors (see below), whose sum is σ = 288071160. Its totient is φ = 132251616.

The previous prime is 198905621. The next prime is 198905711. The reversal of 198905643 is 346509891.

It is a happy number.

198905643 is a `hidden beast` number, since 1 + 9 + 89 + 0 + 564 + 3 = 666.

It is not a de Polignac number, because 198905643 - 2¹⁰ = 198904619 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (198905843) 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 11 ways as a sum of consecutive naturals, for example, 25746 + ... + 32567.

It is an arithmetic number, because the mean of its divisors is an integer number (24005930).

Almost surely, 2^198905643 is an apocalyptic number.

198905643 is a deficient number, since it is larger than the sum of its proper divisors (89165517).

198905643 is a wasteful number, since it uses less digits than its factorization.

198905643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58698 (or 58695 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 45.

The square root of 198905643 is about 14103.3911879377. The cubic root of 198905643 is about 583.7349564724.

The spelling of 198905643 in words is "one hundred ninety-eight million, nine hundred five thousand, six hundred forty-three".