210212120021 has 2 divisors, whose sum is σ = 210212120022. Its totient is φ = 210212120020.

The previous prime is 210212119981. The next prime is 210212120023. The reversal of 210212120021 is 120021212012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 209316315121 + 895804900 = 457511^2 + 29930^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-210212120021 is a prime.

Together with 210212120023, 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 = 210212119978 and 210212120005.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (210212120023) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 105106060010 + 105106060011.

It is an arithmetic number, because the mean of its divisors is an integer number (105106060011).

Almost surely, 2^210212120021 is an apocalyptic number.

It is an amenable number.

210212120021 is a deficient number, since it is larger than the sum of its proper divisors (1).

210212120021 is an equidigital number, since it uses as much as digits as its factorization.

210212120021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 210212120021 its reverse (120021212012), we get a palindrome (330233332033).

The spelling of 210212120021 in words is "two hundred ten billion, two hundred twelve million, one hundred twenty thousand, twenty-one".