2809042981 has 2 divisors, whose sum is σ = 2809042982. Its totient is φ = 2809042980.

The previous prime is 2809042949. The next prime is 2809043047. The reversal of 2809042981 is 1892409082.

2809042981 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1812630625 + 996412356 = 42575^2 + 31566^2 .

It is a cyclic number.

It is not a de Polignac number, because 2809042981 - 2⁵ = 2809042949 is a prime.

It is a super-2 number, since 2×2809042981² = 15781444938210732722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2809042681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1404521490 + 1404521491.

It is an arithmetic number, because the mean of its divisors is an integer number (1404521491).

Almost surely, 2^2809042981 is an apocalyptic number.

It is an amenable number.

2809042981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2809042981 is an equidigital number, since it uses as much as digits as its factorization.

2809042981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 82944, while the sum is 43.

The square root of 2809042981 is about 53000.4054795810. The cubic root of 2809042981 is about 1410.9754631904.

The spelling of 2809042981 in words is "two billion, eight hundred nine million, forty-two thousand, nine hundred eighty-one".