1689745 has 4 divisors (see below), whose sum is σ = 2027700. Its totient is φ = 1351792.

The previous prime is 1689739. The next prime is 1689757. The reversal of 1689745 is 5479861.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 408321 + 1281424 = 639^2 + 1132^2 .

It is a cyclic number.

It is not a de Polignac number, because 1689745 - 2⁵ = 1689713 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a junction number, because it is equal to n+sod(n) for n = 1689698 and 1689707.

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, 168970 + ... + 168979.

It is an arithmetic number, because the mean of its divisors is an integer number (506925).

2^1689745 is an apocalyptic number.

It is an amenable number.

1689745 is a deficient number, since it is larger than the sum of its proper divisors (337955).

1689745 is an equidigital number, since it uses as much as digits as its factorization.

1689745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 337954.

The product of its digits is 60480, while the sum is 40.

The square root of 1689745 is about 1299.9019193770. The cubic root of 1689745 is about 119.1078512854.

The spelling of 1689745 in words is "one million, six hundred eighty-nine thousand, seven hundred forty-five".