6221211221 has 2 divisors, whose sum is σ = 6221211222. Its totient is φ = 6221211220.

The previous prime is 6221211197. The next prime is 6221211239. The reversal of 6221211221 is 1221121226.

6221211221 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 5361900625 + 859310596 = 73225^2 + 29314^2 .

It is a cyclic number.

It is not a de Polignac number, because 6221211221 - 2²² = 6217016917 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 6221211193 and 6221211202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6221210221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3110605610 + 3110605611.

It is an arithmetic number, because the mean of its divisors is an integer number (3110605611).

Almost surely, 2^6221211221 is an apocalyptic number.

It is an amenable number.

6221211221 is a deficient number, since it is larger than the sum of its proper divisors (1).

6221211221 is an equidigital number, since it uses as much as digits as its factorization.

6221211221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 192, while the sum is 20.

The square root of 6221211221 is about 78874.6551244441. The cubic root of 6221211221 is about 1839.1831618685.

Adding to 6221211221 its reverse (1221121226), we get a palindrome (7442332447).

The spelling of 6221211221 in words is "six billion, two hundred twenty-one million, two hundred eleven thousand, two hundred twenty-one".