6822121221 has 6 divisors (see below), whose sum is σ = 9854175110. Its totient is φ = 4548080808.

The previous prime is 6822121217. The next prime is 6822121223. The reversal of 6822121221 is 1221212286.

It can be written as a sum of positive squares in only one way, i.e., 4136290596 + 2685830625 = 64314^2 + 51825^2 .

It is not a de Polignac number, because 6822121221 - 2² = 6822121217 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6822121223) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 379006726 + ... + 379006743.

Almost surely, 2^6822121221 is an apocalyptic number.

It is an amenable number.

6822121221 is a deficient number, since it is larger than the sum of its proper divisors (3032053889).

6822121221 is a wasteful number, since it uses less digits than its factorization.

6822121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 758013475 (or 758013472 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 6822121221 is about 82596.1332085225. The cubic root of 6822121221 is about 1896.5886359643.

The spelling of 6822121221 in words is "six billion, eight hundred twenty-two million, one hundred twenty-one thousand, two hundred twenty-one".