1689305 has 4 divisors (see below), whose sum is σ = 2027172. Its totient is φ = 1351440.

The previous prime is 1689287. The next prime is 1689319. The reversal of 1689305 is 5039861.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5039861 = 1433 ⋅3517.

It can be written as a sum of positive squares in 2 ways, for example, as 222784 + 1466521 = 472^2 + 1211^2 .

It is not a de Polignac number, because 1689305 - 2⁸ = 1689049 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 11.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 168926 + ... + 168935.

It is an arithmetic number, because the mean of its divisors is an integer number (506793).

2^1689305 is an apocalyptic number.

It is an amenable number.

1689305 is a deficient number, since it is larger than the sum of its proper divisors (337867).

1689305 is an equidigital number, since it uses as much as digits as its factorization.

1689305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 337866.

The product of its (nonzero) digits is 6480, while the sum is 32.

The square root of 1689305 is about 1299.7326648200. The cubic root of 1689305 is about 119.0975120519.

The spelling of 1689305 in words is "one million, six hundred eighty-nine thousand, three hundred five".