8211821837 has 2 divisors, whose sum is σ = 8211821838. Its totient is φ = 8211821836.

The previous prime is 8211821833. The next prime is 8211821923. The reversal of 8211821837 is 7381281128.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7981814281 + 230007556 = 89341^2 + 15166^2 .

It is a cyclic number.

It is not a de Polignac number, because 8211821837 - 2² = 8211821833 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 8211821794 and 8211821803.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8211821833) 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, 4105910918 + 4105910919.

It is an arithmetic number, because the mean of its divisors is an integer number (4105910919).

Almost surely, 2^8211821837 is an apocalyptic number.

It is an amenable number.

8211821837 is a deficient number, since it is larger than the sum of its proper divisors (1).

8211821837 is an equidigital number, since it uses as much as digits as its factorization.

8211821837 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 43008, while the sum is 41.

The square root of 8211821837 is about 90619.1030467638. The cubic root of 8211821837 is about 2017.4982783938.

The spelling of 8211821837 in words is "eight billion, two hundred eleven million, eight hundred twenty-one thousand, eight hundred thirty-seven".