6561441673 has 2 divisors, whose sum is σ = 6561441674. Its totient is φ = 6561441672.

The previous prime is 6561441647. The next prime is 6561441701. The reversal of 6561441673 is 3761441656.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6008110144 + 553331529 = 77512^2 + 23523^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6561441673 is a prime.

It is not a weakly prime, because it can be changed into another prime (6561441773) 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, 3280720836 + 3280720837.

It is an arithmetic number, because the mean of its divisors is an integer number (3280720837).

Almost surely, 2^6561441673 is an apocalyptic number.

It is an amenable number.

6561441673 is a deficient number, since it is larger than the sum of its proper divisors (1).

6561441673 is an equidigital number, since it uses as much as digits as its factorization.

6561441673 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 362880, while the sum is 43.

The square root of 6561441673 is about 81002.7263306612. The cubic root of 6561441673 is about 1872.1174478911.

The spelling of 6561441673 in words is "six billion, five hundred sixty-one million, four hundred forty-one thousand, six hundred seventy-three".