198799813 has 2 divisors, whose sum is σ = 198799814. Its totient is φ = 198799812.

The previous prime is 198799771. The next prime is 198799829. The reversal of 198799813 is 318997891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 166332609 + 32467204 = 12897^2 + 5698^2 .

It is an emirp because it is prime and its reverse (318997891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 198799813 - 2⁹ = 198799301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198793813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99399906 + 99399907.

It is an arithmetic number, because the mean of its divisors is an integer number (99399907).

Almost surely, 2^198799813 is an apocalyptic number.

It is an amenable number.

198799813 is a deficient number, since it is larger than the sum of its proper divisors (1).

198799813 is an equidigital number, since it uses as much as digits as its factorization.

198799813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 979776, while the sum is 55.

The square root of 198799813 is about 14099.6387542376. The cubic root of 198799813 is about 583.6314105078.

It can be divided in two parts, 19879 and 9813, that added together give a palindrome (29692).

The spelling of 198799813 in words is "one hundred ninety-eight million, seven hundred ninety-nine thousand, eight hundred thirteen".