198975109 has 2 divisors, whose sum is σ = 198975110. Its totient is φ = 198975108.

The previous prime is 198975103. The next prime is 198975121. The reversal of 198975109 is 901579891.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 195160900 + 3814209 = 13970^2 + 1953^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198975109 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198975103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99487554 + 99487555.

It is an arithmetic number, because the mean of its divisors is an integer number (99487555).

Almost surely, 2^198975109 is an apocalyptic number.

It is an amenable number.

198975109 is a deficient number, since it is larger than the sum of its proper divisors (1).

198975109 is an equidigital number, since it uses as much as digits as its factorization.

198975109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 204120, while the sum is 49.

The square root of 198975109 is about 14105.8537139728. The cubic root of 198975109 is about 583.8029032842.

The spelling of 198975109 in words is "one hundred ninety-eight million, nine hundred seventy-five thousand, one hundred nine".