20021022021221 has 48 divisors (see below), whose sum is σ = 21968314797744. Its totient is φ = 18138193920000.

The previous prime is 20021022021191. The next prime is 20021022021239. The reversal of 20021022021221 is 12212022012002.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 549541998721 + 19471480022500 = 741311^2 + 4412650^2 .

It is not a de Polignac number, because 20021022021221 - 2¹⁸ = 20021021759077 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20021022021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20021022024221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 22725336701 + ... + 22725337581.

It is an arithmetic number, because the mean of its divisors is an integer number (457673224953).

Almost surely, 2^{20021022021221} is an apocalyptic number.

It is an amenable number.

20021022021221 is a deficient number, since it is larger than the sum of its proper divisors (1947292776523).

20021022021221 is an equidigital number, since it uses as much as digits as its factorization.

20021022021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2214 (or 2143 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

Adding to 20021022021221 its reverse (12212022012002), we get a palindrome (32233044033223).

The spelling of 20021022021221 in words is "twenty trillion, twenty-one billion, twenty-two million, twenty-one thousand, two hundred twenty-one".