2101811 has 2 divisors, whose sum is σ = 2101812. Its totient is φ = 2101810.

The previous prime is 2101807. The next prime is 2101817. The reversal of 2101811 is 1181012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2101811 - 2² = 2101807 is a prime.

It is not a weakly prime, because it can be changed into another prime (2101817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1050905 + 1050906.

It is an arithmetic number, because the mean of its divisors is an integer number (1050906).

2^2101811 is an apocalyptic number.

2101811 is a deficient number, since it is larger than the sum of its proper divisors (1).

2101811 is an equidigital number, since it uses as much as digits as its factorization.

2101811 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 14.

The square root of 2101811 is about 1449.7623943254. The cubic root of 2101811 is about 128.0947174913.

Adding to 2101811 its reverse (1181012), we get a palindrome (3282823).

The spelling of 2101811 in words is "two million, one hundred one thousand, eight hundred eleven".