198969209 has 2 divisors, whose sum is σ = 198969210. Its totient is φ = 198969208.

The previous prime is 198969167. The next prime is 198969223. The reversal of 198969209 is 902969891.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 123765625 + 75203584 = 11125^2 + 8672^2 .

It is a cyclic number.

It is not a de Polignac number, because 198969209 - 2¹² = 198965113 is a prime.

It is a super-2 number, since 2×198969209² = 79177492260171362, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (198969259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99484604 + 99484605.

It is an arithmetic number, because the mean of its divisors is an integer number (99484605).

Almost surely, 2^198969209 is an apocalyptic number.

It is an amenable number.

198969209 is a deficient number, since it is larger than the sum of its proper divisors (1).

198969209 is an equidigital number, since it uses as much as digits as its factorization.

198969209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 629856, while the sum is 53.

The square root of 198969209 is about 14105.6445793874. The cubic root of 198969209 is about 583.7971329290.

The spelling of 198969209 in words is "one hundred ninety-eight million, nine hundred sixty-nine thousand, two hundred nine".