1689605 has 8 divisors (see below), whose sum is σ = 2082552. Its totient is φ = 1315008.

The previous prime is 1689601. The next prime is 1689607. The reversal of 1689605 is 5069861.

It can be written as a sum of positive squares in 4 ways, for example, as 717409 + 972196 = 847^2 + 986^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1689605 - 2² = 1689601 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1689601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4382 + ... + 4751.

It is an arithmetic number, because the mean of its divisors is an integer number (260319).

2^1689605 is an apocalyptic number.

It is an amenable number.

1689605 is a deficient number, since it is larger than the sum of its proper divisors (392947).

1689605 is an equidigital number, since it uses as much as digits as its factorization.

1689605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9175.

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 1689605 is about 1299.8480680449. The cubic root of 1689605 is about 119.1045617240.

The spelling of 1689605 in words is "one million, six hundred eighty-nine thousand, six hundred five".