2001664 has 36 divisors (see below), whose sum is σ = 4570384. Its totient is φ = 857088.

The previous prime is 2001653. The next prime is 2001673. The reversal of 2001664 is 4661002.

It is a hoax number, since the sum of its digits (19) coincides with the sum of the digits of its distinct prime factors.

It is a zygodrome in base 13.

It is a congruent 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, 1234 + ... + 2350.

2^2001664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2001664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2285192).

2001664 is an abundant number, since it is smaller than the sum of its proper divisors (2568720).

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

2001664 is an equidigital number, since it uses as much as digits as its factorization.

2001664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1140 (or 1126 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 2001664 is about 1414.8017528969. The cubic root of 2001664 is about 126.0270371139.

Adding to 2001664 its reverse (4661002), we get a palindrome (6662666).

The spelling of 2001664 in words is "two million, one thousand, six hundred sixty-four".