2809000081 has 2 divisors, whose sum is σ = 2809000082. Its totient is φ = 2809000080.

The previous prime is 2809000079. The next prime is 2809000133. The reversal of 2809000081 is 1800009082.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2809000000 + 81 = 53000^2 + 9^2 .

It is a cyclic number.

It is not a de Polignac number, because 2809000081 - 2¹ = 2809000079 is a prime.

It is a super-2 number, since 2×2809000081² = 15780962910116013122, which contains 22 as substring.

Together with 2809000079, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (2809000681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1404500040 + 1404500041.

It is an arithmetic number, because the mean of its divisors is an integer number (1404500041).

Almost surely, 2^2809000081 is an apocalyptic number.

It is an amenable number.

2809000081 is a deficient number, since it is larger than the sum of its proper divisors (1).

2809000081 is an equidigital number, since it uses as much as digits as its factorization.

2809000081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 2809000081 is about 53000.0007641509. Note that the first 3 decimals coincide. The cubic root of 2809000081 is about 1410.9682802986.

It can be divided in two parts, 28090000 and 81, that multiplied together give a square (2275290000 = 47700²).

The spelling of 2809000081 in words is "two billion, eight hundred nine million, eighty-one", and thus it is an aban number.