199490609 has 2 divisors, whose sum is σ = 199490610. Its totient is φ = 199490608.

The previous prime is 199490593. The next prime is 199490651. The reversal of 199490609 is 906094991.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 186923584 + 12567025 = 13672^2 + 3545^2 .

It is a cyclic number.

It is not a de Polignac number, because 199490609 - 2⁴ = 199490593 is a prime.

It is not a weakly prime, because it can be changed into another prime (199490659) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99745304 + 99745305.

It is an arithmetic number, because the mean of its divisors is an integer number (99745305).

Almost surely, 2^199490609 is an apocalyptic number.

It is an amenable number.

199490609 is a deficient number, since it is larger than the sum of its proper divisors (1).

199490609 is an equidigital number, since it uses as much as digits as its factorization.

199490609 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 157464, while the sum is 47.

The square root of 199490609 is about 14124.1144501169. The cubic root of 199490609 is about 584.3066360931.

The spelling of 199490609 in words is "one hundred ninety-nine million, four hundred ninety thousand, six hundred nine".