1221222021120 has 144 divisors (see below), whose sum is σ = 4232536406280. Its totient is φ = 325659181056.

The previous prime is 1221222020983. The next prime is 1221222021121. The reversal of 1221222021120 is 211202221221.

It is a happy number.

1221222021120 is a `hidden beast` number, since 1 + 2 + 212 + 220 + 211 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

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 = 1221222021093 and 1221222021102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221222021121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6533394 + ... + 6717713.

Almost surely, 2^{1221222021120} is an apocalyptic number.

1221222021120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221222021120 is an abundant number, since it is smaller than the sum of its proper divisors (3011314385160).

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

1221222021120 is a wasteful number, since it uses less digits than its factorization.

1221222021120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13251140 (or 13251117 counting only the distinct ones).

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

Adding to 1221222021120 its reverse (211202221221), we get a palindrome (1432424242341).

The spelling of 1221222021120 in words is "one trillion, two hundred twenty-one billion, two hundred twenty-two million, twenty-one thousand, one hundred twenty".