1221020221120 has 112 divisors (see below), whose sum is σ = 3355820129088. Its totient is φ = 414490521600.

The previous prime is 1221020221111. The next prime is 1221020221121. The reversal of 1221020221120 is 211220201221.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (112).

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 1221020221094 and 1221020221103.

It is not an unprimeable number, because it can be changed into a prime (1221020221121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2472267 + ... + 2924746.

It is an arithmetic number, because the mean of its divisors is an integer number (29962679724).

Almost surely, 2^{1221020221120} is an apocalyptic number.

1221020221120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221020221120 is an abundant number, since it is smaller than the sum of its proper divisors (2134799907968).

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

1221020221120 is a wasteful number, since it uses less digits than its factorization.

1221020221120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5397138 (or 5397128 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 1221020221120 its reverse (211220201221), we get a palindrome (1432240422341).

The spelling of 1221020221120 in words is "one trillion, two hundred twenty-one billion, twenty million, two hundred twenty-one thousand, one hundred twenty".