1211221121020 has 24 divisors (see below), whose sum is σ = 2543658312384. Its totient is φ = 484470551616.

The previous prime is 1211221121017. The next prime is 1211221121041. The reversal of 1211221121020 is 201211221121.

It is a junction number, because it is equal to n+sod(n) for n = 1211221120985 and 1211221121003.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 556707 + ... + 1652986.

It is an arithmetic number, because the mean of its divisors is an integer number (105985763016).

Almost surely, 2^{1211221121020} is an apocalyptic number.

1211221121020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211221121020 is an abundant number, since it is smaller than the sum of its proper divisors (1332437191364).

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

1211221121020 is a wasteful number, since it uses less digits than its factorization.

1211221121020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2237109 (or 2237107 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 1211221121020 its reverse (201211221121), we get a palindrome (1412432342141).

The spelling of 1211221121020 in words is "one trillion, two hundred eleven billion, two hundred twenty-one million, one hundred twenty-one thousand, twenty".