198908081 has 2 divisors, whose sum is σ = 198908082. Its totient is φ = 198908080.

The previous prime is 198908051. The next prime is 198908111. The reversal of 198908081 is 180809891.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (198908051) and next prime (198908111).

It can be written as a sum of positive squares in only one way, i.e., 193071025 + 5837056 = 13895^2 + 2416^2 .

It is an emirp because it is prime and its reverse (180809891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 198908081 - 2¹⁰ = 198907057 is a prime.

It is a super-2 number, since 2×198908081² = 79128849374205122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (198908051) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99454040 + 99454041.

It is an arithmetic number, because the mean of its divisors is an integer number (99454041).

Almost surely, 2^198908081 is an apocalyptic number.

It is an amenable number.

198908081 is a deficient number, since it is larger than the sum of its proper divisors (1).

198908081 is an equidigital number, since it uses as much as digits as its factorization.

198908081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 41472, while the sum is 44.

The square root of 198908081 is about 14103.4776207856. The cubic root of 198908081 is about 583.7373414224.

The spelling of 198908081 in words is "one hundred ninety-eight million, nine hundred eight thousand, eighty-one".