21212122220101 has 2 divisors, whose sum is σ = 21212122220102. Its totient is φ = 21212122220100.

The previous prime is 21212122220099. The next prime is 21212122220123. The reversal of 21212122220101 is 10102222121212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16174674150625 + 5037448069476 = 4021775^2 + 2244426^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212122220101 - 2¹ = 21212122220099 is a prime.

Together with 21212122220099, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21212122220141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606061110050 + 10606061110051.

It is an arithmetic number, because the mean of its divisors is an integer number (10606061110051).

Almost surely, 2^{21212122220101} is an apocalyptic number.

It is an amenable number.

21212122220101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212122220101 is an equidigital number, since it uses as much as digits as its factorization.

21212122220101 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 21212122220101 its reverse (10102222121212), we get a palindrome (31314344341313).

The spelling of 21212122220101 in words is "twenty-one trillion, two hundred twelve billion, one hundred twenty-two million, two hundred twenty thousand, one hundred one".