1221220320222 has 96 divisors (see below), whose sum is σ = 2876294703744. Its totient is φ = 344613528000.

The previous prime is 1221220320217. The next prime is 1221220320227. The reversal of 1221220320222 is 2220230221221.

It is an interprime number because it is at equal distance from previous prime (1221220320217) and next prime (1221220320227).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221220320227) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 124469697 + ... + 124479507.

It is an arithmetic number, because the mean of its divisors is an integer number (29961403164).

Almost surely, 2^{1221220320222} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221220320222, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1438147351872).

1221220320222 is an abundant number, since it is smaller than the sum of its proper divisors (1655074383522).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221220320222 is a wasteful number, since it uses less digits than its factorization.

1221220320222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15014 (or 15007 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 21.

Adding to 1221220320222 its reverse (2220230221221), we get a palindrome (3441450541443).

Subtracting 1221220320222 from its reverse (2220230221221), we obtain a palindrome (999009900999).

The spelling of 1221220320222 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, three hundred twenty thousand, two hundred twenty-two".