8518335183221 has 2 divisors, whose sum is σ = 8518335183222. Its totient is φ = 8518335183220.

The previous prime is 8518335183157. The next prime is 8518335183301. The reversal of 8518335183221 is 1223815338158.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4689715080625 + 3828620102596 = 2165575^2 + 1956686^2 .

It is a cyclic number.

It is not a de Polignac number, because 8518335183221 - 2⁶ = 8518335183157 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8518335183221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8518335143221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4259167591610 + 4259167591611.

It is an arithmetic number, because the mean of its divisors is an integer number (4259167591611).

Almost surely, 2^{8518335183221} is an apocalyptic number.

It is an amenable number.

8518335183221 is a deficient number, since it is larger than the sum of its proper divisors (1).

8518335183221 is an equidigital number, since it uses as much as digits as its factorization.

8518335183221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1382400, while the sum is 50.

The spelling of 8518335183221 in words is "eight trillion, five hundred eighteen billion, three hundred thirty-five million, one hundred eighty-three thousand, two hundred twenty-one".