2806561081 has 4 divisors (see below), whose sum is σ = 2812623232. Its totient is φ = 2800498932.

The previous prime is 2806561063. The next prime is 2806561097. The reversal of 2806561081 is 1801656082.

2806561081 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 a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1801656082 = 2 ⋅900828041.

It is a cyclic number.

It is not a de Polignac number, because 2806561081 - 2¹⁵ = 2806528313 is a prime.

It is a super-2 number, since 2×2806561081² = 15753570202767777122, which contains 22 as substring.

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 2806561081.

It is not an unprimeable number, because it can be changed into a prime (2806561981) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3030381 + ... + 3031306.

It is an arithmetic number, because the mean of its divisors is an integer number (703155808).

Almost surely, 2^2806561081 is an apocalyptic number.

It is an amenable number.

2806561081 is a deficient number, since it is larger than the sum of its proper divisors (6062151).

2806561081 is an equidigital number, since it uses as much as digits as its factorization.

2806561081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6062150.

The product of its (nonzero) digits is 23040, while the sum is 37.

The square root of 2806561081 is about 52976.9863336902. The cubic root of 2806561081 is about 1410.5597899655.

The spelling of 2806561081 in words is "two billion, eight hundred six million, five hundred sixty-one thousand, eighty-one".