198242909 has 2 divisors, whose sum is σ = 198242910. Its totient is φ = 198242908.

The previous prime is 198242893. The next prime is 198242951. The reversal of 198242909 is 909242891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 105062500 + 93180409 = 10250^2 + 9653^2 .

It is a cyclic number.

It is not a de Polignac number, because 198242909 - 2⁴ = 198242893 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 198242909.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198241909) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99121454 + 99121455.

It is an arithmetic number, because the mean of its divisors is an integer number (99121455).

Almost surely, 2^198242909 is an apocalyptic number.

It is an amenable number.

198242909 is a deficient number, since it is larger than the sum of its proper divisors (1).

198242909 is an equidigital number, since it uses as much as digits as its factorization.

198242909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 93312, while the sum is 44.

The square root of 198242909 is about 14079.8760292838. The cubic root of 198242909 is about 583.0859193129.

The spelling of 198242909 in words is "one hundred ninety-eight million, two hundred forty-two thousand, nine hundred nine".