998009 has 2 divisors, whose sum is σ = 998010. Its totient is φ = 998008.

The previous prime is 997991. The next prime is 998017. The reversal of 998009 is 900899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 727609 + 270400 = 853^2 + 520^2 .

It is a cyclic number.

It is not a de Polignac number, because 998009 - 2¹² = 993913 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 998009.

It is not a weakly prime, because it can be changed into another prime (998029) 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, 499004 + 499005.

It is an arithmetic number, because the mean of its divisors is an integer number (499005).

2⁹⁹⁸⁰⁰⁹ is an apocalyptic number.

It is an amenable number.

998009 is a deficient number, since it is larger than the sum of its proper divisors (1).

998009 is an equidigital number, since it uses as much as digits as its factorization.

998009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 35.

The square root of 998009 is about 999.0040039960. The cubic root of 998009 is about 99.9335892392.

The spelling of 998009 in words is "nine hundred ninety-eight thousand, nine".