518994817109 has 2 divisors, whose sum is σ = 518994817110. Its totient is φ = 518994817108.

The previous prime is 518994817043. The next prime is 518994817123. The reversal of 518994817109 is 901718499815.

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., 328877016484 + 190117800625 = 573478^2 + 436025^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-518994817109 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (518994817189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 259497408554 + 259497408555.

It is an arithmetic number, because the mean of its divisors is an integer number (259497408555).

Almost surely, 2^518994817109 is an apocalyptic number.

It is an amenable number.

518994817109 is a deficient number, since it is larger than the sum of its proper divisors (1).

518994817109 is an equidigital number, since it uses as much as digits as its factorization.

518994817109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6531840, while the sum is 62.

The spelling of 518994817109 in words is "five hundred eighteen billion, nine hundred ninety-four million, eight hundred seventeen thousand, one hundred nine".