518745579830221 has 2 divisors, whose sum is σ = 518745579830222. Its totient is φ = 518745579830220.

The previous prime is 518745579830197. The next prime is 518745579830249. The reversal of 518745579830221 is 122038975547815.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 434341487221321 + 84404092608900 = 20840861^2 + 9187170^2 .

It is a cyclic number.

It is not a de Polignac number, because 518745579830221 - 2³⁹ = 518195824016333 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (518745579830921) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 259372789915110 + 259372789915111.

It is an arithmetic number, because the mean of its divisors is an integer number (259372789915111).

Almost surely, 2^{518745579830221} is an apocalyptic number.

It is an amenable number.

518745579830221 is a deficient number, since it is larger than the sum of its proper divisors (1).

518745579830221 is an equidigital number, since it uses as much as digits as its factorization.

518745579830221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 169344000, while the sum is 67.

The spelling of 518745579830221 in words is "five hundred eighteen trillion, seven hundred forty-five billion, five hundred seventy-nine million, eight hundred thirty thousand, two hundred twenty-one".