7818068821 has 2 divisors, whose sum is σ = 7818068822. Its totient is φ = 7818068820.

The previous prime is 7818068773. The next prime is 7818068879. The reversal of 7818068821 is 1288608187.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4627400625 + 3190668196 = 68025^2 + 56486^2 .

It is an emirp because it is prime and its reverse (1288608187) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7818068821 - 2¹⁷ = 7817937749 is a prime.

It is a super-2 number, since 2×7818068821² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7818068021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3909034410 + 3909034411.

It is an arithmetic number, because the mean of its divisors is an integer number (3909034411).

Almost surely, 2^7818068821 is an apocalyptic number.

It is an amenable number.

7818068821 is a deficient number, since it is larger than the sum of its proper divisors (1).

7818068821 is an equidigital number, since it uses as much as digits as its factorization.

7818068821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 344064, while the sum is 49.

The square root of 7818068821 is about 88419.8440453273. The cubic root of 7818068821 is about 1984.7226671067.

The spelling of 7818068821 in words is "seven billion, eight hundred eighteen million, sixty-eight thousand, eight hundred twenty-one".