6810645581 has 2 divisors, whose sum is σ = 6810645582. Its totient is φ = 6810645580.

The previous prime is 6810645571. The next prime is 6810645599. The reversal of 6810645581 is 1855460186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3535372681 + 3275272900 = 59459^2 + 57230^2 .

It is a cyclic number.

It is not a de Polignac number, because 6810645581 - 2²⁶ = 6743536717 is a prime.

It is a super-2 number, since 2×6810645581² = 92769786459989655122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6810645571) 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, 3405322790 + 3405322791.

It is an arithmetic number, because the mean of its divisors is an integer number (3405322791).

Almost surely, 2^6810645581 is an apocalyptic number.

It is an amenable number.

6810645581 is a deficient number, since it is larger than the sum of its proper divisors (1).

6810645581 is an equidigital number, since it uses as much as digits as its factorization.

6810645581 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 230400, while the sum is 44.

The square root of 6810645581 is about 82526.6355851249. The cubic root of 6810645581 is about 1895.5246079942.

The spelling of 6810645581 in words is "six billion, eight hundred ten million, six hundred forty-five thousand, five hundred eighty-one".