518221045717 has 2 divisors, whose sum is σ = 518221045718. Its totient is φ = 518221045716.

The previous prime is 518221045673. The next prime is 518221045721. The reversal of 518221045717 is 717540122815.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 263282898321 + 254938147396 = 513111^2 + 504914^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-518221045717 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (518221085717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 259110522858 + 259110522859.

It is an arithmetic number, because the mean of its divisors is an integer number (259110522859).

Almost surely, 2^518221045717 is an apocalyptic number.

It is an amenable number.

518221045717 is a deficient number, since it is larger than the sum of its proper divisors (1).

518221045717 is an equidigital number, since it uses as much as digits as its factorization.

518221045717 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 156800, while the sum is 43.

The spelling of 518221045717 in words is "five hundred eighteen billion, two hundred twenty-one million, forty-five thousand, seven hundred seventeen".