2113805 has 4 divisors (see below), whose sum is σ = 2536572. Its totient is φ = 1691040.

The previous prime is 2113801. The next prime is 2113819. The reversal of 2113805 is 5083112.

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

It can be written as a sum of positive squares in 2 ways, for example, as 256036 + 1857769 = 506^2 + 1363^2 .

It is not a de Polignac number, because 2113805 - 2² = 2113801 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2113801) 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, 211376 + ... + 211385.

It is an arithmetic number, because the mean of its divisors is an integer number (634143).

2^2113805 is an apocalyptic number.

It is an amenable number.

2113805 is a deficient number, since it is larger than the sum of its proper divisors (422767).

2113805 is an equidigital number, since it uses as much as digits as its factorization.

2113805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 422766.

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 2113805 is about 1453.8930497117. The cubic root of 2113805 is about 128.3379132939.

Adding to 2113805 its reverse (5083112), we get a palindrome (7196917).

The spelling of 2113805 in words is "two million, one hundred thirteen thousand, eight hundred five".