2105815 has 4 divisors (see below), whose sum is σ = 2526984. Its totient is φ = 1684648.

The previous prime is 2105813. The next prime is 2105819. The reversal of 2105815 is 5185012.

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 2105815 - 2¹ = 2105813 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.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2105813) 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, 210577 + ... + 210586.

It is an arithmetic number, because the mean of its divisors is an integer number (631746).

2^2105815 is an apocalyptic number.

2105815 is a deficient number, since it is larger than the sum of its proper divisors (421169).

2105815 is an equidigital number, since it uses as much as digits as its factorization.

2105815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421168.

The product of its (nonzero) digits is 400, while the sum is 22.

The square root of 2105815 is about 1451.1426532219. The cubic root of 2105815 is about 128.1760070559.

The spelling of 2105815 in words is "two million, one hundred five thousand, eight hundred fifteen".