1221020011120 has 160 divisors (see below), whose sum is σ = 3514673796480. Its totient is φ = 386432317440.

The previous prime is 1221020011097. The next prime is 1221020011177. The reversal of 1221020011120 is 211100201221.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a self number, because there is not a number n which added to its sum of digits gives 1221020011120.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 734100 + ... + 1726540.

It is an arithmetic number, because the mean of its divisors is an integer number (21966711228).

Almost surely, 2^{1221020011120} is an apocalyptic number.

1221020011120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1221020011120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1757336898240).

1221020011120 is an abundant number, since it is smaller than the sum of its proper divisors (2293653785360).

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

1221020011120 is an equidigital number, since it uses as much as digits as its factorization.

1221020011120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 992500 (or 992468 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 1221020011120 its reverse (211100201221), we get a palindrome (1432120212341).

The spelling of 1221020011120 in words is "one trillion, two hundred twenty-one billion, twenty million, eleven thousand, one hundred twenty".