2001666 has 16 divisors (see below), whose sum is σ = 4032000. Its totient is φ = 662448.

The previous prime is 2001653. The next prime is 2001673. The reversal of 2001666 is 6661002.

It is a Curzon 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, 226 + ... + 2013.

It is an arithmetic number, because the mean of its divisors is an integer number (252000).

2^2001666 is an apocalyptic number.

2001666 is an abundant number, since it is smaller than the sum of its proper divisors (2030334).

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

2001666 is a wasteful number, since it uses less digits than its factorization.

2001666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2393.

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 2001666 is about 1414.8024597095. The cubic root of 2001666 is about 126.0270790880.

Adding to 2001666 its reverse (6661002), we get a palindrome (8662668).

The spelling of 2001666 in words is "two million, one thousand, six hundred sixty-six".