998989 has 2 divisors, whose sum is σ = 998990. Its totient is φ = 998988.

The previous prime is 998983. The next prime is 999007. The reversal of 998989 is 989899.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 917764 + 81225 = 958^2 + 285^2 .

It is a cyclic number.

It is not a de Polignac number, because 998989 - 2⁵ = 998957 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (998983) 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, 499494 + 499495.

It is an arithmetic number, because the mean of its divisors is an integer number (499495).

2⁹⁹⁸⁹⁸⁹ is an apocalyptic number.

It is an amenable number.

998989 is a deficient number, since it is larger than the sum of its proper divisors (1).

998989 is an equidigital number, since it uses as much as digits as its factorization.

998989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 419904, while the sum is 52.

The square root of 998989 is about 999.4943721702. The cubic root of 998989 is about 99.9662886367.

The spelling of 998989 in words is "nine hundred ninety-eight thousand, nine hundred eighty-nine".