2605865 has 4 divisors (see below), whose sum is σ = 3127044. Its totient is φ = 2084688.

The previous prime is 2605849. The next prime is 2605871. The reversal of 2605865 is 5685062.

It is a happy number.

2605865 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5685062 = 2 ⋅2842531.

It can be written as a sum of positive squares in 2 ways, for example, as 1038361 + 1567504 = 1019^2 + 1252^2 .

It is a cyclic number.

It is not a de Polignac number, because 2605865 - 2⁴ = 2605849 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 260582 + ... + 260591.

It is an arithmetic number, because the mean of its divisors is an integer number (781761).

2^2605865 is an apocalyptic number.

It is an amenable number.

2605865 is a deficient number, since it is larger than the sum of its proper divisors (521179).

2605865 is an equidigital number, since it uses as much as digits as its factorization.

2605865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 521178.

The product of its (nonzero) digits is 14400, while the sum is 32.

The square root of 2605865 is about 1614.2691844919. The cubic root of 2605865 is about 137.6102036613.

The spelling of 2605865 in words is "two million, six hundred five thousand, eight hundred sixty-five".