21212120212201 has 2 divisors, whose sum is σ = 21212120212202. Its totient is φ = 21212120212200.

The previous prime is 21212120212177. The next prime is 21212120212319. The reversal of 21212120212201 is 10221202121212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12986833875625 + 8225286336576 = 3603725^2 + 2867976^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21212120212201 is a prime.

It is not a weakly prime, because it can be changed into another prime (21212120210201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606060106100 + 10606060106101.

It is an arithmetic number, because the mean of its divisors is an integer number (10606060106101).

Almost surely, 2^{21212120212201} is an apocalyptic number.

It is an amenable number.

21212120212201 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212120212201 is an equidigital number, since it uses as much as digits as its factorization.

21212120212201 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 19.

Adding to 21212120212201 its reverse (10221202121212), we get a palindrome (31433322333413).

The spelling of 21212120212201 in words is "twenty-one trillion, two hundred twelve billion, one hundred twenty million, two hundred twelve thousand, two hundred one".