2021110211221 has 4 divisors (see below), whose sum is σ = 2023113294700. Its totient is φ = 2019107127744.

The previous prime is 2021110211203. The next prime is 2021110211231. The reversal of 2021110211221 is 1221120111202.

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 987014432196 + 1034095779025 = 993486^2 + 1016905^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021110211221 - 2²⁷ = 2020975993493 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2021110211195 and 2021110211204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2021110211231) 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, 1001540226 + ... + 1001542243.

It is an arithmetic number, because the mean of its divisors is an integer number (505778323675).

Almost surely, 2^{2021110211221} is an apocalyptic number.

It is an amenable number.

2021110211221 is a deficient number, since it is larger than the sum of its proper divisors (2003083479).

2021110211221 is a wasteful number, since it uses less digits than its factorization.

2021110211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2003083478.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 2021110211221 its reverse (1221120111202), we get a palindrome (3242230322423).

The spelling of 2021110211221 in words is "two trillion, twenty-one billion, one hundred ten million, two hundred eleven thousand, two hundred twenty-one".