20212212121 has 2 divisors, whose sum is σ = 20212212122. Its totient is φ = 20212212120.

The previous prime is 20212212109. The next prime is 20212212161. The reversal of 20212212121 is 12121221202.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19268493721 + 943718400 = 138811^2 + 30720^2 .

It is a cyclic number.

It is not a de Polignac number, because 20212212121 - 2⁷ = 20212211993 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20212212095 and 20212212104.

It is not a weakly prime, because it can be changed into another prime (20212212161) 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, 10106106060 + 10106106061.

It is an arithmetic number, because the mean of its divisors is an integer number (10106106061).

Almost surely, 2^20212212121 is an apocalyptic number.

It is an amenable number.

20212212121 is a deficient number, since it is larger than the sum of its proper divisors (1).

20212212121 is an equidigital number, since it uses as much as digits as its factorization.

20212212121 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 20212212121 its reverse (12121221202), we get a palindrome (32333433323).

The spelling of 20212212121 in words is "twenty billion, two hundred twelve million, two hundred twelve thousand, one hundred twenty-one".