121221111020 has 96 divisors (see below), whose sum is σ = 265901916672. Its totient is φ = 46368000000.

The previous prime is 121221110993. The next prime is 121221111043. The reversal of 121221111020 is 20111122121.

It is a junction number, because it is equal to n+sod(n) for n = 121221110986 and 121221111004.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 37633010 + ... + 37636230.

It is an arithmetic number, because the mean of its divisors is an integer number (2769811632).

Almost surely, 2^121221111020 is an apocalyptic number.

121221111020 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 121221111020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (132950958336).

121221111020 is an abundant number, since it is smaller than the sum of its proper divisors (144680805652).

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

121221111020 is a wasteful number, since it uses less digits than its factorization.

121221111020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3963 (or 3961 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 121221111020 its reverse (20111122121), we get a palindrome (141332233141).

The spelling of 121221111020 in words is "one hundred twenty-one billion, two hundred twenty-one million, one hundred eleven thousand, twenty".