2021211220121 has 4 divisors (see below), whose sum is σ = 2059347280932. Its totient is φ = 1983075159312.

The previous prime is 2021211220097. The next prime is 2021211220129. The reversal of 2021211220121 is 1210221121202.

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 1068254542096 + 952956678025 = 1033564^2 + 976195^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021211220121 - 2³⁸ = 1746333313177 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 2021211220121.

It is not an unprimeable number, because it can be changed into a prime (2021211220129) 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, 19068030326 + ... + 19068030431.

It is an arithmetic number, because the mean of its divisors is an integer number (514836820233).

Almost surely, 2^{2021211220121} is an apocalyptic number.

It is an amenable number.

2021211220121 is a deficient number, since it is larger than the sum of its proper divisors (38136060811).

2021211220121 is an equidigital number, since it uses as much as digits as its factorization.

2021211220121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38136060810.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 2021211220121 its reverse (1210221121202), we get a palindrome (3231432341323).

The spelling of 2021211220121 in words is "two trillion, twenty-one billion, two hundred eleven million, two hundred twenty thousand, one hundred twenty-one".