6516643897 has 2 divisors, whose sum is σ = 6516643898. Its totient is φ = 6516643896.

The previous prime is 6516643891. The next prime is 6516643919. The reversal of 6516643897 is 7983466156.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3337488441 + 3179155456 = 57771^2 + 56384^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6516643897 is a prime.

It is not a weakly prime, because it can be changed into another prime (6516643891) 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, 3258321948 + 3258321949.

It is an arithmetic number, because the mean of its divisors is an integer number (3258321949).

Almost surely, 2^6516643897 is an apocalyptic number.

It is an amenable number.

6516643897 is a deficient number, since it is larger than the sum of its proper divisors (1).

6516643897 is an equidigital number, since it uses as much as digits as its factorization.

6516643897 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6531840, while the sum is 55.

The square root of 6516643897 is about 80725.7325578406. The cubic root of 6516643897 is about 1867.8471317946.

The spelling of 6516643897 in words is "six billion, five hundred sixteen million, six hundred forty-three thousand, eight hundred ninety-seven".