198659813 has 4 divisors (see below), whose sum is σ = 216719808. Its totient is φ = 180599820.

The previous prime is 198659789. The next prime is 198659819. The reversal of 198659813 is 318956891.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198659813 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 (198659819) 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, 9029981 + ... + 9030002.

It is an arithmetic number, because the mean of its divisors is an integer number (54179952).

Almost surely, 2^198659813 is an apocalyptic number.

It is an amenable number.

198659813 is a deficient number, since it is larger than the sum of its proper divisors (18059995).

198659813 is a wasteful number, since it uses less digits than its factorization.

198659813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18059994.

The product of its digits is 466560, while the sum is 50.

The square root of 198659813 is about 14094.6732136648. The cubic root of 198659813 is about 583.4943755275.

The spelling of 198659813 in words is "one hundred ninety-eight million, six hundred fifty-nine thousand, eight hundred thirteen".