6564720917 has 2 divisors, whose sum is σ = 6564720918. Its totient is φ = 6564720916.

The previous prime is 6564720889. The next prime is 6564720959. The reversal of 6564720917 is 7190274656.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5904539281 + 660181636 = 76841^2 + 25694^2 .

It is a cyclic number.

It is not a de Polignac number, because 6564720917 - 2⁸ = 6564720661 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6564720317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3282360458 + 3282360459.

It is an arithmetic number, because the mean of its divisors is an integer number (3282360459).

Almost surely, 2^6564720917 is an apocalyptic number.

It is an amenable number.

6564720917 is a deficient number, since it is larger than the sum of its proper divisors (1).

6564720917 is an equidigital number, since it uses as much as digits as its factorization.

6564720917 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 635040, while the sum is 47.

The square root of 6564720917 is about 81022.9653678511. The cubic root of 6564720917 is about 1872.4292750662.

The spelling of 6564720917 in words is "six billion, five hundred sixty-four million, seven hundred twenty thousand, nine hundred seventeen".