1220220111221 has 2 divisors, whose sum is σ = 1220220111222. Its totient is φ = 1220220111220.

The previous prime is 1220220111203. The next prime is 1220220111307. The reversal of 1220220111221 is 1221110220221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 798590662321 + 421629448900 = 893639^2 + 649330^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220220111221 - 2⁶ = 1220220111157 is a prime.

It is a super-2 number, since 2×1220220111221² (a number of 25 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1220220111221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1220220171221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610110055610 + 610110055611.

It is an arithmetic number, because the mean of its divisors is an integer number (610110055611).

Almost surely, 2^{1220220111221} is an apocalyptic number.

It is an amenable number.

1220220111221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1220220111221 is an equidigital number, since it uses as much as digits as its factorization.

1220220111221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 1220220111221 its reverse (1221110220221), we get a palindrome (2441330331442).

The spelling of 1220220111221 in words is "one trillion, two hundred twenty billion, two hundred twenty million, one hundred eleven thousand, two hundred twenty-one".