2109811 has 4 divisors (see below), whose sum is σ = 2301624. Its totient is φ = 1918000.

The previous prime is 2109799. The next prime is 2109841. The reversal of 2109811 is 1189012.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2109811 - 2¹⁹ = 1585523 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

2109811 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2109841) 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, 95890 + ... + 95911.

It is an arithmetic number, because the mean of its divisors is an integer number (575406).

2^2109811 is an apocalyptic number.

2109811 is a deficient number, since it is larger than the sum of its proper divisors (191813).

2109811 is a wasteful number, since it uses less digits than its factorization.

2109811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 191812.

The product of its (nonzero) digits is 144, while the sum is 22.

The square root of 2109811 is about 1452.5188466936. The cubic root of 2109811 is about 128.2570315344.

The spelling of 2109811 in words is "two million, one hundred nine thousand, eight hundred eleven".