20201222210021 has 2 divisors, whose sum is σ = 20201222210022. Its totient is φ = 20201222210020.

The previous prime is 20201222210011. The next prime is 20201222210023. The reversal of 20201222210021 is 12001222210202.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18687559513921 + 1513662696100 = 4322911^2 + 1230310^2 .

It is a cyclic number.

It is not a de Polignac number, because 20201222210021 - 2²⁶ = 20201155101157 is a prime.

Together with 20201222210023, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20201222210023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10100611105010 + 10100611105011.

It is an arithmetic number, because the mean of its divisors is an integer number (10100611105011).

Almost surely, 2^{20201222210021} is an apocalyptic number.

It is an amenable number.

20201222210021 is a deficient number, since it is larger than the sum of its proper divisors (1).

20201222210021 is an equidigital number, since it uses as much as digits as its factorization.

20201222210021 is an evil number, because the sum of its binary digits is even.

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

Adding to 20201222210021 its reverse (12001222210202), we get a palindrome (32202444420223).

The spelling of 20201222210021 in words is "twenty trillion, two hundred one billion, two hundred twenty-two million, two hundred ten thousand, twenty-one".