998399789 has 2 divisors, whose sum is σ = 998399790. Its totient is φ = 998399788.

The previous prime is 998399777. The next prime is 998399807. The reversal of 998399789 is 987993899.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 946054564 + 52345225 = 30758^2 + 7235^2 .

It is a cyclic number.

It is not a de Polignac number, because 998399789 - 2⁸ = 998399533 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (998399189) 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, 499199894 + 499199895.

It is an arithmetic number, because the mean of its divisors is an integer number (499199895).

Almost surely, 2^998399789 is an apocalyptic number.

It is an amenable number.

998399789 is a deficient number, since it is larger than the sum of its proper divisors (1).

998399789 is an equidigital number, since it uses as much as digits as its factorization.

998399789 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 79361856, while the sum is 71.

The square root of 998399789 is about 31597.4649141351. The cubic root of 998399789 is about 999.4663115607.

The spelling of 998399789 in words is "nine hundred ninety-eight million, three hundred ninety-nine thousand, seven hundred eighty-nine".