2021221020 has 192 divisors, whose sum is σ = 7128253440. Its totient is φ = 416489472.

The previous prime is 2021221009. The next prime is 2021221021. The reversal of 2021221020 is 201221202.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a junction number, because it is equal to n+sod(n) for n = 2021220987 and 2021221005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021221021) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 230476 + ... + 239084.

It is an arithmetic number, because the mean of its divisors is an integer number (37126320).

Almost surely, 2^2021221020 is an apocalyptic number.

2021221020 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 2021221020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3564126720).

2021221020 is an abundant number, since it is smaller than the sum of its proper divisors (5107032420).

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

2021221020 is a wasteful number, since it uses less digits than its factorization.

2021221020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8684 (or 8682 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 2021221020 is about 44957.9917256098. The cubic root of 2021221020 is about 1264.3615164922.

Adding to 2021221020 its reverse (201221202), we get a palindrome (2222442222).

The spelling of 2021221020 in words is "two billion, twenty-one million, two hundred twenty-one thousand, twenty".