2105689 has 4 divisors (see below), whose sum is σ = 2109456. Its totient is φ = 2101924.

The previous prime is 2105681. The next prime is 2105693. The reversal of 2105689 is 9865012.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2105689 - 2³ = 2105681 is a prime.

It is a Smith number, since the sum of its digits (31) 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 self number, because there is not a number n which added to its sum of digits gives 2105689.

It is not an unprimeable number, because it can be changed into a prime (2105681) 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 in 3 ways as a sum of consecutive naturals, for example, 859 + ... + 2224.

It is an arithmetic number, because the mean of its divisors is an integer number (527364).

2^2105689 is an apocalyptic number.

It is an amenable number.

2105689 is a deficient number, since it is larger than the sum of its proper divisors (3767).

2105689 is an equidigital number, since it uses as much as digits as its factorization.

2105689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3766.

The product of its (nonzero) digits is 4320, while the sum is 31.

The square root of 2105689 is about 1451.0992385085. The cubic root of 2105689 is about 128.1734505636.

The spelling of 2105689 in words is "two million, one hundred five thousand, six hundred eighty-nine".