2021121108221 has 2 divisors, whose sum is σ = 2021121108222. Its totient is φ = 2021121108220.

The previous prime is 2021121108199. The next prime is 2021121108241. The reversal of 2021121108221 is 1228011211202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1819838772196 + 201282336025 = 1349014^2 + 448645^2 .

It is a cyclic number.

It is not a de Polignac number, because 2021121108221 - 2³⁴ = 2003941239037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2021121108241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010560554110 + 1010560554111.

It is an arithmetic number, because the mean of its divisors is an integer number (1010560554111).

Almost surely, 2^{2021121108221} is an apocalyptic number.

It is an amenable number.

2021121108221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021121108221 is an equidigital number, since it uses as much as digits as its factorization.

2021121108221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 256, while the sum is 23.

Adding to 2021121108221 its reverse (1228011211202), we get a palindrome (3249132319423).

The spelling of 2021121108221 in words is "two trillion, twenty-one billion, one hundred twenty-one million, one hundred eight thousand, two hundred twenty-one".