2001656 has 16 divisors (see below), whose sum is σ = 3780240. Its totient is φ = 993600.

The previous prime is 2001653. The next prime is 2001673. The reversal of 2001656 is 6561002.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001653) 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, 380 + ... + 2036.

It is an arithmetic number, because the mean of its divisors is an integer number (236265).

2^2001656 is an apocalyptic number.

It is an amenable number.

2001656 is a deficient number, since it is larger than the sum of its proper divisors (1778584).

2001656 is a wasteful number, since it uses less digits than its factorization.

2001656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1814 (or 1810 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 2001656 is about 1414.7989256428. The cubic root of 2001656 is about 126.0268692173.

Adding to 2001656 its reverse (6561002), we get a palindrome (8562658).

The spelling of 2001656 in words is "two million, one thousand, six hundred fifty-six".