2021100111221 has 2 divisors, whose sum is σ = 2021100111222. Its totient is φ = 2021100111220.

The previous prime is 2021100111137. The next prime is 2021100111223. The reversal of 2021100111221 is 1221110011202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1019869732996 + 1001230378225 = 1009886^2 + 1000615^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2021100111221 is a prime.

It is a super-2 number, since 2×2021100111221² (a number of 25 digits) contains 22 as substring.

Together with 2021100111223, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 2021100111196 and 2021100111205.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021100111223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010550055610 + 1010550055611.

It is an arithmetic number, because the mean of its divisors is an integer number (1010550055611).

Almost surely, 2^{2021100111221} is an apocalyptic number.

It is an amenable number.

2021100111221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021100111221 is an equidigital number, since it uses as much as digits as its factorization.

2021100111221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 2021100111221 its reverse (1221110011202), we get a palindrome (3242210122423).

The spelling of 2021100111221 in words is "two trillion, twenty-one billion, one hundred million, one hundred eleven thousand, two hundred twenty-one".