1668666 has 8 divisors (see below), whose sum is σ = 3337344. Its totient is φ = 556220.

The previous prime is 1668649. The next prime is 1668679. The reversal of 1668666 is 6668661.

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

1668666 is an admirable number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 139050 + ... + 139061.

It is an arithmetic number, because the mean of its divisors is an integer number (417168).

2^1668666 is an apocalyptic number.

1668666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1668666 is a wasteful number, since it uses less digits than its factorization.

1668666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278116.

The product of its digits is 62208, while the sum is 39.

The square root of 1668666 is about 1291.7685551212. The cubic root of 1668666 is about 118.6105006405.

The spelling of 1668666 in words is "one million, six hundred sixty-eight thousand, six hundred sixty-six".