1689643 has 4 divisors (see below), whose sum is σ = 1707160. Its totient is φ = 1672128.

The previous prime is 1689641. The next prime is 1689659. The reversal of 1689643 is 3469861.

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

It is a cyclic number.

It is not a de Polignac number, because 1689643 - 2¹ = 1689641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1689641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8613 + ... + 8806.

It is an arithmetic number, because the mean of its divisors is an integer number (426790).

2^1689643 is an apocalyptic number.

1689643 is a deficient number, since it is larger than the sum of its proper divisors (17517).

1689643 is an equidigital number, since it uses as much as digits as its factorization.

1689643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17516.

The product of its digits is 31104, while the sum is 37.

The square root of 1689643 is about 1299.8626850556. The cubic root of 1689643 is about 119.1054546229.

It can be divided in two parts, 1689 and 643, that added together give a palindrome (2332).

The spelling of 1689643 in words is "one million, six hundred eighty-nine thousand, six hundred forty-three".