2221122661 has 2 divisors, whose sum is σ = 2221122662. Its totient is φ = 2221122660.

The previous prime is 2221122619. The next prime is 2221122671. The reversal of 2221122661 is 1662211222.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2181357025 + 39765636 = 46705^2 + 6306^2 .

It is a cyclic number.

It is not a de Polignac number, because 2221122661 - 2¹⁷ = 2220991589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2221122611) 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, 1110561330 + 1110561331.

It is an arithmetic number, because the mean of its divisors is an integer number (1110561331).

Almost surely, 2^2221122661 is an apocalyptic number.

It is an amenable number.

2221122661 is a deficient number, since it is larger than the sum of its proper divisors (1).

2221122661 is an equidigital number, since it uses as much as digits as its factorization.

2221122661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1152, while the sum is 25.

The square root of 2221122661 is about 47128.7880281257. The cubic root of 2221122661 is about 1304.7406130484.

Adding to 2221122661 its reverse (1662211222), we get a palindrome (3883333883).

The spelling of 2221122661 in words is "two billion, two hundred twenty-one million, one hundred twenty-two thousand, six hundred sixty-one".