1698989 has 4 divisors (see below), whose sum is σ = 1704156. Its totient is φ = 1693824.

The previous prime is 1698971. The next prime is 1699001. The reversal of 1698989 is 9898961.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9898961 = 59 ⋅167779.

It can be written as a sum of positive squares in 2 ways, for example, as 990025 + 708964 = 995^2 + 842^2 .

It is a cyclic number.

It is not a de Polignac number, because 1698989 - 2²⁰ = 650413 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1698089) 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 in 3 ways as a sum of consecutive naturals, for example, 2054 + ... + 2759.

It is an arithmetic number, because the mean of its divisors is an integer number (426039).

2^1698989 is an apocalyptic number.

It is an amenable number.

1698989 is a deficient number, since it is larger than the sum of its proper divisors (5167).

1698989 is an equidigital number, since it uses as much as digits as its factorization.

1698989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5166.

The product of its digits is 279936, while the sum is 50.

The square root of 1698989 is about 1303.4527225795. The cubic root of 1698989 is about 119.3246554520.

The spelling of 1698989 in words is "one million, six hundred ninety-eight thousand, nine hundred eighty-nine".