20211202222121 has 2 divisors, whose sum is σ = 20211202222122. Its totient is φ = 20211202222120.

The previous prime is 20211202222117. The next prime is 20211202222139. The reversal of 20211202222121 is 12122220211202.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18549258403225 + 1661943818896 = 4306885^2 + 1289164^2 .

It is a cyclic number.

It is not a de Polignac number, because 20211202222121 - 2² = 20211202222117 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20211202222093 and 20211202222102.

It is not a weakly prime, because it can be changed into another prime (20211202222151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105601111060 + 10105601111061.

It is an arithmetic number, because the mean of its divisors is an integer number (10105601111061).

Almost surely, 2^{20211202222121} is an apocalyptic number.

It is an amenable number.

20211202222121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20211202222121 is an equidigital number, since it uses as much as digits as its factorization.

20211202222121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 20211202222121 its reverse (12122220211202), we get a palindrome (32333422433323).

The spelling of 20211202222121 in words is "twenty trillion, two hundred eleven billion, two hundred two million, two hundred twenty-two thousand, one hundred twenty-one".