1220220212221 has 4 divisors (see below), whose sum is σ = 1220397860700. Its totient is φ = 1220042563744.

The previous prime is 1220220212173. The next prime is 1220220212297. The reversal of 1220220212221 is 1222120220221.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 175452076900 + 1044768135321 = 418870^2 + 1022139^2 .

It is a cyclic number.

It is not a de Polignac number, because 1220220212221 - 2³⁹ = 670464398333 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1220220212021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 88813936 + ... + 88827673.

It is an arithmetic number, because the mean of its divisors is an integer number (305099465175).

Almost surely, 2^{1220220212221} is an apocalyptic number.

It is an amenable number.

1220220212221 is a deficient number, since it is larger than the sum of its proper divisors (177648479).

1220220212221 is an equidigital number, since it uses as much as digits as its factorization.

1220220212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177648478.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 1220220212221 its reverse (1222120220221), we get a palindrome (2442340432442).

The spelling of 1220220212221 in words is "one trillion, two hundred twenty billion, two hundred twenty million, two hundred twelve thousand, two hundred twenty-one".