2805561 has 24 divisors (see below), whose sum is σ = 4683744. Its totient is φ = 1599360.

The previous prime is 2805533. The next prime is 2805577. The reversal of 2805561 is 1655082.

It is not a de Polignac number, because 2805561 - 2⁵ = 2805529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2805511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 850 + ... + 2516.

It is an arithmetic number, because the mean of its divisors is an integer number (195156).

2^2805561 is an apocalyptic number.

It is an amenable number.

2805561 is a deficient number, since it is larger than the sum of its proper divisors (1878183).

2805561 is a wasteful number, since it uses less digits than its factorization.

2805561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1701 (or 1698 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 2805561 is about 1674.9808954134. The cubic root of 2805561 is about 141.0392225273.

The spelling of 2805561 in words is "two million, eight hundred five thousand, five hundred sixty-one".