6565543997 has 2 divisors, whose sum is σ = 6565543998. Its totient is φ = 6565543996.

The previous prime is 6565543981. The next prime is 6565544047. The reversal of 6565543997 is 7993455656.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3776225401 + 2789318596 = 61451^2 + 52814^2 .

It is a cyclic number.

It is not a de Polignac number, because 6565543997 - 2⁴ = 6565543981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6565543597) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3282771998 + 3282771999.

It is an arithmetic number, because the mean of its divisors is an integer number (3282771999).

Almost surely, 2^6565543997 is an apocalyptic number.

It is an amenable number.

6565543997 is a deficient number, since it is larger than the sum of its proper divisors (1).

6565543997 is an equidigital number, since it uses as much as digits as its factorization.

6565543997 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30618000, while the sum is 59.

The square root of 6565543997 is about 81028.0445092932. The cubic root of 6565543997 is about 1872.5075264091.

The spelling of 6565543997 in words is "six billion, five hundred sixty-five million, five hundred forty-three thousand, nine hundred ninety-seven".