1221021222120 has 96 divisors (see below), whose sum is σ = 4535221691520. Its totient is φ = 279090564480.

The previous prime is 1221021222119. The next prime is 1221021222139. The reversal of 1221021222120 is 212221201221.

It is a happy number.

1221021222120 is a `hidden beast` number, since 1 + 2 + 210 + 212 + 221 + 20 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1221021222093 and 1221021222102.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 242263596 + ... + 242268635.

It is an arithmetic number, because the mean of its divisors is an integer number (47241892620).

Almost surely, 2^{1221021222120} is an apocalyptic number.

1221021222120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221021222120 is an abundant number, since it is smaller than the sum of its proper divisors (3314200469400).

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

1221021222120 is a wasteful number, since it uses less digits than its factorization.

1221021222120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 484532255 (or 484532248 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 1221021222120 its reverse (212221201221), we get a palindrome (1433242423341).

The spelling of 1221021222120 in words is "one trillion, two hundred twenty-one billion, twenty-one million, two hundred twenty-two thousand, one hundred twenty".