2001811 has 16 divisors (see below), whose sum is σ = 2407680. Its totient is φ = 1628640.

The previous prime is 2001809. The next prime is 2001833. The reversal of 2001811 is 1181002.

It is a cyclic number.

It is not a de Polignac number, because 2001811 - 2¹ = 2001809 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2001791 and 2001800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15216 + ... + 15346.

It is an arithmetic number, because the mean of its divisors is an integer number (150480).

2^2001811 is an apocalyptic number.

2001811 is a deficient number, since it is larger than the sum of its proper divisors (405869).

2001811 is a wasteful number, since it uses less digits than its factorization.

2001811 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 2001811 is about 1414.8537026845. The cubic root of 2001811 is about 126.0301221340.

Adding to 2001811 its reverse (1181002), we get a palindrome (3182813).

The spelling of 2001811 in words is "two million, one thousand, eight hundred eleven".