6818072821 has 4 divisors (see below), whose sum is σ = 7792083232. Its totient is φ = 5844062412.

The previous prime is 6818072797. The next prime is 6818072837. The reversal of 6818072821 is 1282708186.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6818072821 is a prime.

It is a super-2 number, since 2×6818072821² = 92972233984917796082, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6818072861) 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 in 3 ways as a sum of consecutive naturals, for example, 487005195 + ... + 487005208.

It is an arithmetic number, because the mean of its divisors is an integer number (1948020808).

Almost surely, 2^6818072821 is an apocalyptic number.

It is an amenable number.

6818072821 is a deficient number, since it is larger than the sum of its proper divisors (974010411).

6818072821 is an equidigital number, since it uses as much as digits as its factorization.

6818072821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 974010410.

The product of its (nonzero) digits is 86016, while the sum is 43.

The square root of 6818072821 is about 82571.6223711270. The cubic root of 6818072821 is about 1896.2134022952.

The spelling of 6818072821 in words is "six billion, eight hundred eighteen million, seventy-two thousand, eight hundred twenty-one".