1685665 has 8 divisors (see below), whose sum is σ = 2061288. Its totient is φ = 1322880.

The previous prime is 1685627. The next prime is 1685681. The reversal of 1685665 is 5665861.

It can be written as a sum of positive squares in 4 ways, for example, as 150544 + 1535121 = 388^2 + 1239^2 .

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

It is not a de Polignac number, because 1685665 - 2⁹ = 1685153 is a prime.

It is a d-powerful number, because it can be written as 1 + 6 + 8⁴ + 5² + 6⁴ + 6⁸ + 5⁴ .

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2916 + ... + 3445.

It is an arithmetic number, because the mean of its divisors is an integer number (257661).

2^1685665 is an apocalyptic number.

It is an amenable number.

1685665 is a deficient number, since it is larger than the sum of its proper divisors (375623).

1685665 is an equidigital number, since it uses as much as digits as its factorization.

1685665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6419.

The product of its digits is 43200, while the sum is 37.

The square root of 1685665 is about 1298.3316217361. The cubic root of 1685665 is about 119.0119094547.

The spelling of 1685665 in words is "one million, six hundred eighty-five thousand, six hundred sixty-five".