1668621 has 8 divisors (see below), whose sum is σ = 2247264. Its totient is φ = 1101200.

The previous prime is 1668619. The next prime is 1668629. The reversal of 1668621 is 1268661.

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 1668621 - 2¹ = 1668619 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1668629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2451 + ... + 3056.

It is an arithmetic number, because the mean of its divisors is an integer number (280908).

2^1668621 is an apocalyptic number.

It is an amenable number.

1668621 is a deficient number, since it is larger than the sum of its proper divisors (578643).

1668621 is a wasteful number, since it uses less digits than its factorization.

1668621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5611.

The product of its digits is 3456, while the sum is 30.

The square root of 1668621 is about 1291.7511370229. The cubic root of 1668621 is about 118.6094344154.

The spelling of 1668621 in words is "one million, six hundred sixty-eight thousand, six hundred twenty-one".