2805813 has 8 divisors (see below), whose sum is σ = 4156800. Its totient is φ = 1870524.

The previous prime is 2805809. The next prime is 2805827. The reversal of 2805813 is 3185082.

It is a happy number.

2805813 is a `hidden beast` number, since 2 + 80 + 581 + 3 = 666.

It is not a de Polignac number, because 2805813 - 2² = 2805809 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 103919 = 2805813 / (2 + 8 + 0 + 5 + 8 + 1 + 3).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2805113) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51933 + ... + 51986.

It is an arithmetic number, because the mean of its divisors is an integer number (519600).

2^2805813 is an apocalyptic number.

It is an amenable number.

2805813 is a deficient number, since it is larger than the sum of its proper divisors (1350987).

2805813 is a wasteful number, since it uses less digits than its factorization.

2805813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103928 (or 103922 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 27.

The square root of 2805813 is about 1675.0561184629. The cubic root of 2805813 is about 141.0434451908.

It can be divided in two parts, 2 and 805813, that added together give a triangular number (805815 = T₁₂₆₉).

The spelling of 2805813 in words is "two million, eight hundred five thousand, eight hundred thirteen".