20210020221221 has 4 divisors (see below), whose sum is σ = 20261974001100. Its totient is φ = 20158066441344.

The previous prime is 20210020221191. The next prime is 20210020221227. The reversal of 20210020221221 is 12212202001202.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13803907360321 + 6406112860900 = 3715361^2 + 2531030^2 .

It is a cyclic number.

It is not a de Polignac number, because 20210020221221 - 2¹⁴ = 20210020204837 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 20210020221221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20210020221227) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25976889356 + ... + 25976890133.

It is an arithmetic number, because the mean of its divisors is an integer number (5065493500275).

Almost surely, 2^{20210020221221} is an apocalyptic number.

It is an amenable number.

20210020221221 is a deficient number, since it is larger than the sum of its proper divisors (51953779879).

20210020221221 is an equidigital number, since it uses as much as digits as its factorization.

20210020221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51953779878.

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

Adding to 20210020221221 its reverse (12212202001202), we get a palindrome (32422222222423).

The spelling of 20210020221221 in words is "twenty trillion, two hundred ten billion, twenty million, two hundred twenty-one thousand, two hundred twenty-one".