198609421 has 4 divisors (see below), whose sum is σ = 201330172. Its totient is φ = 195888672.

The previous prime is 198609409. The next prime is 198609427. The reversal of 198609421 is 124906891.

198609421 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 124906891 = 1367 ⋅91373.

It can be written as a sum of positive squares in 2 ways, for example, as 151536100 + 47073321 = 12310^2 + 6861^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198609421 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198609427) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1360266 + ... + 1360411.

It is an arithmetic number, because the mean of its divisors is an integer number (50332543).

Almost surely, 2^198609421 is an apocalyptic number.

It is an amenable number.

198609421 is a deficient number, since it is larger than the sum of its proper divisors (2720751).

198609421 is an equidigital number, since it uses as much as digits as its factorization.

198609421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2720750.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 198609421 is about 14092.8854745932. The cubic root of 198609421 is about 583.4450350081.

The spelling of 198609421 in words is "one hundred ninety-eight million, six hundred nine thousand, four hundred twenty-one".