1689728 has 32 divisors (see below), whose sum is σ = 3455760. Its totient is φ = 822528.

The previous prime is 1689719. The next prime is 1689739. The reversal of 1689728 is 8279861.

It is a tau number, because it is divible by the number of its divisors (32).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5351 + ... + 5657.

2^1689728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1689728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1727880).

1689728 is an abundant number, since it is smaller than the sum of its proper divisors (1766032).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1689728 is an equidigital number, since it uses as much as digits as its factorization.

1689728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 364 (or 352 counting only the distinct ones).

The product of its digits is 48384, while the sum is 41.

The square root of 1689728 is about 1299.8953804057. The cubic root of 1689728 is about 119.1074518483.

The spelling of 1689728 in words is "one million, six hundred eighty-nine thousand, seven hundred twenty-eight".