21212210101 has 2 divisors, whose sum is σ = 21212210102. Its totient is φ = 21212210100.

The previous prime is 21212210099. The next prime is 21212210113. The reversal of 21212210101 is 10101221212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21173160100 + 39050001 = 145510^2 + 6249^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212210101 - 2¹ = 21212210099 is a prime.

Together with 21212210099, 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 (21212216101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606105050 + 10606105051.

It is an arithmetic number, because the mean of its divisors is an integer number (10606105051).

Almost surely, 2^21212210101 is an apocalyptic number.

It is an amenable number.

21212210101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212210101 is an equidigital number, since it uses as much as digits as its factorization.

21212210101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21212210101 its reverse (10101221212), we get a palindrome (31313431313).

The spelling of 21212210101 in words is "twenty-one billion, two hundred twelve million, two hundred ten thousand, one hundred one".