6543447881 has 2 divisors, whose sum is σ = 6543447882. Its totient is φ = 6543447880.

The previous prime is 6543447871. The next prime is 6543447907. The reversal of 6543447881 is 1887443456.

6543447881 is digitally balanced in base 3, 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., 4794870025 + 1748577856 = 69245^2 + 41816^2 .

It is a cyclic number.

It is not a de Polignac number, because 6543447881 - 2³⁰ = 5469706057 is a prime.

It is a super-2 number, since 2×6543447881² = 85633420342726780322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (6543447851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3271723940 + 3271723941.

It is an arithmetic number, because the mean of its divisors is an integer number (3271723941).

Almost surely, 2^6543447881 is an apocalyptic number.

It is an amenable number.

6543447881 is a deficient number, since it is larger than the sum of its proper divisors (1).

6543447881 is an equidigital number, since it uses as much as digits as its factorization.

6543447881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2580480, while the sum is 50.

The square root of 6543447881 is about 80891.5810267051. The cubic root of 6543447881 is about 1870.4045452466.

The spelling of 6543447881 in words is "six billion, five hundred forty-three million, four hundred forty-seven thousand, eight hundred eighty-one".