198721169 has 2 divisors, whose sum is σ = 198721170. Its totient is φ = 198721168.

The previous prime is 198721163. The next prime is 198721199. The reversal of 198721169 is 961127891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 126675025 + 72046144 = 11255^2 + 8488^2 .

It is an emirp because it is prime and its reverse (961127891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 198721169 - 2⁴ = 198721153 is a prime.

It is a super-2 number, since 2×198721169² = 78980206017453122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (198721163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99360584 + 99360585.

It is an arithmetic number, because the mean of its divisors is an integer number (99360585).

Almost surely, 2^198721169 is an apocalyptic number.

It is an amenable number.

198721169 is a deficient number, since it is larger than the sum of its proper divisors (1).

198721169 is an equidigital number, since it uses as much as digits as its factorization.

198721169 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 54432, while the sum is 44.

The square root of 198721169 is about 14096.8496125908. The cubic root of 198721169 is about 583.5544400088.

The spelling of 198721169 in words is "one hundred ninety-eight million, seven hundred twenty-one thousand, one hundred sixty-nine".