1221022220221 has 8 divisors (see below), whose sum is σ = 1249617983040. Its totient is φ = 1192757044512.

The previous prime is 1221022220161. The next prime is 1221022220261. The reversal of 1221022220221 is 1220222201221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221022220221 - 2¹⁷ = 1221022089149 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 (1221022220261) 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 7 ways as a sum of consecutive naturals, for example, 82639305 + ... + 82654078.

It is an arithmetic number, because the mean of its divisors is an integer number (156202247880).

Almost surely, 2^{1221022220221} is an apocalyptic number.

It is an amenable number.

1221022220221 is a deficient number, since it is larger than the sum of its proper divisors (28595762819).

1221022220221 is an equidigital number, since it uses as much as digits as its factorization.

1221022220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165293555.

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

Adding to 1221022220221 its reverse (1220222201221), we get a palindrome (2441244421442).

The spelling of 1221022220221 in words is "one trillion, two hundred twenty-one billion, twenty-two million, two hundred twenty thousand, two hundred twenty-one".