2021121021220 has 144 divisors (see below), whose sum is σ = 4995855966528. Its totient is φ = 684765446400.

The previous prime is 2021121021217. The next prime is 2021121021373. The reversal of 2021121021220 is 221201211202.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 2021121021194 and 2021121021203.

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 47 ways as a sum of consecutive naturals, for example, 51747019 + ... + 51786061.

It is an arithmetic number, because the mean of its divisors is an integer number (34693444212).

Almost surely, 2^{2021121021220} is an apocalyptic number.

2021121021220 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 2021121021220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2497927983264).

2021121021220 is an abundant number, since it is smaller than the sum of its proper divisors (2974734945308).

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

2021121021220 is a wasteful number, since it uses less digits than its factorization.

2021121021220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39690 (or 39681 counting only the distinct ones).

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

Adding to 2021121021220 its reverse (221201211202), we get a palindrome (2242322232422).

The spelling of 2021121021220 in words is "two trillion, twenty-one billion, one hundred twenty-one million, twenty-one thousand, two hundred twenty".