2605861 has 4 divisors (see below), whose sum is σ = 2623500. Its totient is φ = 2588224.

The previous prime is 2605849. The next prime is 2605871. The reversal of 2605861 is 1685062.

2605861 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: 1685062 = 2 ⋅842531.

It can be written as a sum of positive squares in 2 ways, for example, as 93636 + 2512225 = 306^2 + 1585^2 .

It is a cyclic number.

It is not a de Polignac number, because 2605861 - 2⁹ = 2605349 is a prime.

It is a super-4 number, since 4×2605861⁴ (a number of 27 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2605871) by changing a digit.

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, 8596 + ... + 8893.

It is an arithmetic number, because the mean of its divisors is an integer number (655875).

2^2605861 is an apocalyptic number.

It is an amenable number.

2605861 is a deficient number, since it is larger than the sum of its proper divisors (17639).

2605861 is a wasteful number, since it uses less digits than its factorization.

2605861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17638.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 2605861 is about 1614.2679455406. The cubic root of 2605861 is about 137.6101332507.

The spelling of 2605861 in words is "two million, six hundred five thousand, eight hundred sixty-one".