1668685 has 4 divisors (see below), whose sum is σ = 2002428. Its totient is φ = 1334944.

The previous prime is 1668683. The next prime is 1668721. The reversal of 1668685 is 5868661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5868661 = 643 ⋅9127.

It can be written as a sum of positive squares in 2 ways, for example, as 243049 + 1425636 = 493^2 + 1194^2 .

It is a cyclic number.

It is not a de Polignac number, because 1668685 - 2¹ = 1668683 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 6.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668683) 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, 166864 + ... + 166873.

It is an arithmetic number, because the mean of its divisors is an integer number (500607).

2^1668685 is an apocalyptic number.

It is an amenable number.

1668685 is a deficient number, since it is larger than the sum of its proper divisors (333743).

1668685 is an equidigital number, since it uses as much as digits as its factorization.

1668685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 333742.

The product of its digits is 69120, while the sum is 40.

The square root of 1668685 is about 1291.7759093589. The cubic root of 1668685 is about 118.6109508186.

The spelling of 1668685 in words is "one million, six hundred sixty-eight thousand, six hundred eighty-five".