198343021 has 4 divisors (see below), whose sum is σ = 198838044. Its totient is φ = 197848000.

The previous prime is 198343001. The next prime is 198343031. The reversal of 198343021 is 120343891.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 184009225 + 14333796 = 13565^2 + 3786^2 .

It is a cyclic number.

It is not a de Polignac number, because 198343021 - 2⁹ = 198342509 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198343001) 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 3 ways as a sum of consecutive naturals, for example, 246910 + ... + 247711.

It is an arithmetic number, because the mean of its divisors is an integer number (49709511).

Almost surely, 2^198343021 is an apocalyptic number.

It is an amenable number.

198343021 is a deficient number, since it is larger than the sum of its proper divisors (495023).

198343021 is an equidigital number, since it uses as much as digits as its factorization.

198343021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 495022.

The product of its (nonzero) digits is 5184, while the sum is 31.

The square root of 198343021 is about 14083.4307255015. The cubic root of 198343021 is about 583.1840549358.

The spelling of 198343021 in words is "one hundred ninety-eight million, three hundred forty-three thousand, twenty-one".