221211001222121 has 2 divisors, whose sum is σ = 221211001222122. Its totient is φ = 221211001222120.

The previous prime is 221211001222051. The next prime is 221211001222129. The reversal of 221211001222121 is 121222100112122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 213451077301225 + 7759923920896 = 14609965^2 + 2785664^2 .

It is a cyclic number.

It is not a de Polignac number, because 221211001222121 - 2¹⁰ = 221211001221097 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221211001222093 and 221211001222102.

It is not a weakly prime, because it can be changed into another prime (221211001222129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110605500611060 + 110605500611061.

It is an arithmetic number, because the mean of its divisors is an integer number (110605500611061).

Almost surely, 2^{221211001222121} is an apocalyptic number.

It is an amenable number.

221211001222121 is a deficient number, since it is larger than the sum of its proper divisors (1).

221211001222121 is an equidigital number, since it uses as much as digits as its factorization.

221211001222121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 128, while the sum is 20.

Adding to 221211001222121 its reverse (121222100112122), we get a palindrome (342433101334243).

The spelling of 221211001222121 in words is "two hundred twenty-one trillion, two hundred eleven billion, one million, two hundred twenty-two thousand, one hundred twenty-one".