198858817 has 2 divisors, whose sum is σ = 198858818. Its totient is φ = 198858816.

The previous prime is 198858773. The next prime is 198858853. The reversal of 198858817 is 718858891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 190191681 + 8667136 = 13791^2 + 2944^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198858817 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (198858217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99429408 + 99429409.

It is an arithmetic number, because the mean of its divisors is an integer number (99429409).

Almost surely, 2^198858817 is an apocalyptic number.

It is an amenable number.

198858817 is a deficient number, since it is larger than the sum of its proper divisors (1).

198858817 is an equidigital number, since it uses as much as digits as its factorization.

198858817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1290240, while the sum is 55.

The square root of 198858817 is about 14101.7309930377. The cubic root of 198858817 is about 583.6891456080.

The spelling of 198858817 in words is "one hundred ninety-eight million, eight hundred fifty-eight thousand, eight hundred seventeen".