2105665 has 4 divisors (see below), whose sum is σ = 2526804. Its totient is φ = 1684528.

The previous prime is 2105641. The next prime is 2105669. The reversal of 2105665 is 5665012.

2105665 is nontrivially palindromic in base 11.

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 318096 + 1787569 = 564^2 + 1337^2 .

It is a cyclic number.

It is not a de Polignac number, because 2105665 - 2¹¹ = 2103617 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2105669) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 210562 + ... + 210571.

It is an arithmetic number, because the mean of its divisors is an integer number (631701).

2^2105665 is an apocalyptic number.

It is an amenable number.

2105665 is a deficient number, since it is larger than the sum of its proper divisors (421139).

2105665 is an equidigital number, since it uses as much as digits as its factorization.

2105665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 421138.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 2105665 is about 1451.0909688920. The cubic root of 2105665 is about 128.1729636012.

The spelling of 2105665 in words is "two million, one hundred five thousand, six hundred sixty-five".