2021221000000 has 196 divisors, whose sum is σ = 5026466676028. Its totient is φ = 806400000000.

The previous prime is 2021220999991. The next prime is 2021221000037. The reversal of 2021221000000 is 1221202.

It can be written as a sum of positive squares in 14 ways, for example, as 1092325980736 + 928895019264 = 1045144^2 + 963792^2 .

It is a Harshad number since it is a multiple of its sum of digits (10).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 420997600 + ... + 421002400.

It is an arithmetic number, because the mean of its divisors is an integer number (25645238143).

Almost surely, 2^{2021221000000} is an apocalyptic number.

2021221000000 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 2021221000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2513233338014).

2021221000000 is an abundant number, since it is smaller than the sum of its proper divisors (3005245676028).

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

2021221000000 is an frugal number, since it uses more digits than its factorization.

2021221000000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5264 (or 5229 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 2021221000000 its reverse (1221202), we get a palindrome (2021222221202).

The spelling of 2021221000000 in words is "two trillion, twenty-one billion, two hundred twenty-one million", and thus it is an aban number.