2221321261 has 2 divisors, whose sum is σ = 2221321262. Its totient is φ = 2221321260.

The previous prime is 2221321253. The next prime is 2221321273. The reversal of 2221321261 is 1621231222.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2201017225 + 20304036 = 46915^2 + 4506^2 .

It is a cyclic number.

It is not a de Polignac number, because 2221321261 - 2³ = 2221321253 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2221321231) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1110660630 + 1110660631.

It is an arithmetic number, because the mean of its divisors is an integer number (1110660631).

Almost surely, 2^2221321261 is an apocalyptic number.

It is an amenable number.

2221321261 is a deficient number, since it is larger than the sum of its proper divisors (1).

2221321261 is an equidigital number, since it uses as much as digits as its factorization.

2221321261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 576, while the sum is 22.

The square root of 2221321261 is about 47130.8949734672. The cubic root of 2221321261 is about 1304.7794993539.

Adding to 2221321261 its reverse (1621231222), we get a palindrome (3842552483).

The spelling of 2221321261 in words is "two billion, two hundred twenty-one million, three hundred twenty-one thousand, two hundred sixty-one".