2221204621 has 2 divisors, whose sum is σ = 2221204622. Its totient is φ = 2221204620.

The previous prime is 2221204619. The next prime is 2221204637. The reversal of 2221204621 is 1264021222.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2213702500 + 7502121 = 47050^2 + 2739^2 .

It is a cyclic number.

It is not a de Polignac number, because 2221204621 - 2¹ = 2221204619 is a prime.

Together with 2221204619, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 2221204592 and 2221204601.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2221204681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1110602310 + 1110602311.

It is an arithmetic number, because the mean of its divisors is an integer number (1110602311).

Almost surely, 2^2221204621 is an apocalyptic number.

It is an amenable number.

2221204621 is a deficient number, since it is larger than the sum of its proper divisors (1).

2221204621 is an equidigital number, since it uses as much as digits as its factorization.

2221204621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 2221204621 is about 47129.6575523311. The cubic root of 2221204621 is about 1304.7566612729.

Adding to 2221204621 its reverse (1264021222), we get a palindrome (3485225843).

The spelling of 2221204621 in words is "two billion, two hundred twenty-one million, two hundred four thousand, six hundred twenty-one".