1998589 has 2 divisors, whose sum is σ = 1998590. Its totient is φ = 1998588.

The previous prime is 1998587. The next prime is 1998611. The reversal of 1998589 is 9858991.

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., 1582564 + 416025 = 1258^2 + 645^2 .

It is an emirp because it is prime and its reverse (9858991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1998589 - 2¹ = 1998587 is a prime.

Together with 1998587, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1998587) 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, 999294 + 999295.

It is an arithmetic number, because the mean of its divisors is an integer number (999295).

2^1998589 is an apocalyptic number.

It is an amenable number.

1998589 is a deficient number, since it is larger than the sum of its proper divisors (1).

1998589 is an equidigital number, since it uses as much as digits as its factorization.

1998589 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 233280, while the sum is 49.

The square root of 1998589 is about 1413.7146105208. The cubic root of 1998589 is about 125.9624688756.

The spelling of 1998589 in words is "one million, nine hundred ninety-eight thousand, five hundred eighty-nine".