1221222022121 has 2 divisors, whose sum is σ = 1221222022122. Its totient is φ = 1221222022120.

The previous prime is 1221222022099. The next prime is 1221222022127. The reversal of 1221222022121 is 1212202221221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 982041360400 + 239180661721 = 990980^2 + 489061^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221222022121 is a prime.

It is a super-3 number, since 3×1221222022121³ (a number of 37 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1221222022093 and 1221222022102.

It is not a weakly prime, because it can be changed into another prime (1221222022127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610611011060 + 610611011061.

It is an arithmetic number, because the mean of its divisors is an integer number (610611011061).

Almost surely, 2^{1221222022121} is an apocalyptic number.

It is an amenable number.

1221222022121 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221222022121 is an equidigital number, since it uses as much as digits as its factorization.

1221222022121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 1221222022121 its reverse (1212202221221), we get a palindrome (2433424243342).

The spelling of 1221222022121 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-two million, twenty-two thousand, one hundred twenty-one".