221242242161 has 2 divisors, whose sum is σ = 221242242162. Its totient is φ = 221242242160.

The previous prime is 221242242079. The next prime is 221242242167. The reversal of 221242242161 is 161242242122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 139920883600 + 81321358561 = 374060^2 + 285169^2 .

It is a cyclic number.

It is not a de Polignac number, because 221242242161 - 2¹⁰ = 221242241137 is a prime.

It is not a weakly prime, because it can be changed into another prime (221242242167) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110621121080 + 110621121081.

It is an arithmetic number, because the mean of its divisors is an integer number (110621121081).

Almost surely, 2^221242242161 is an apocalyptic number.

It is an amenable number.

221242242161 is a deficient number, since it is larger than the sum of its proper divisors (1).

221242242161 is an equidigital number, since it uses as much as digits as its factorization.

221242242161 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6144, while the sum is 29.

Adding to 221242242161 its reverse (161242242122), we get a palindrome (382484484283).

The spelling of 221242242161 in words is "two hundred twenty-one billion, two hundred forty-two million, two hundred forty-two thousand, one hundred sixty-one".