2021121000000 has 294 divisors, whose sum is σ = 7241412582170. Its totient is φ = 538963200000.

The previous prime is 2021120999999. The next prime is 2021121000091. The reversal of 2021121000000 is 1211202.

It can be written as a sum of positive squares in 7 ways, for example, as 2016422720064 + 4698279936 = 1420008^2 + 68544^2 .

It is a Harshad number since it is a multiple of its sum of digits (9).

It is an unprimeable number.

It is a polite number, since it can be written in 41 ways as a sum of consecutive naturals, for example, 8887716 + ... + 9112284.

Almost surely, 2^{2021121000000} is an apocalyptic number.

2021121000000 is a gapful number since it is divisible by the number (20) 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 2021121000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3620706291085).

2021121000000 is an abundant number, since it is smaller than the sum of its proper divisors (5220291582170).

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

2021121000000 is an frugal number, since it uses more digits than its factorization.

2021121000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224617 (or 224579 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 9.

Adding to 2021121000000 its reverse (1211202), we get a palindrome (2021122211202).

The spelling of 2021121000000 in words is "two trillion, twenty-one billion, one hundred twenty-one million", and thus it is an aban number.