198009856 has 44 divisors (see below), whose sum is σ = 431835120. Its totient is φ = 89999360.

The previous prime is 198009853. The next prime is 198009859. The reversal of 198009856 is 658900891.

It is an interprime number because it is at equal distance from previous prime (198009853) and next prime (198009859).

It is a tau number, because it is divible by the number of its divisors (44).

It is not an unprimeable number, because it can be changed into a prime (198009853) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2475 + ... + 20053.

Almost surely, 2^198009856 is an apocalyptic number.

198009856 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 198009856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (215917560).

198009856 is an abundant number, since it is smaller than the sum of its proper divisors (233825264).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

198009856 is a wasteful number, since it uses less digits than its factorization.

198009856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17610 (or 17592 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 46.

The square root of 198009856 is about 14071.5974928222. The cubic root of 198009856 is about 582.8573391186.

The spelling of 198009856 in words is "one hundred ninety-eight million, nine thousand, eight hundred fifty-six".