21212102101 has 2 divisors, whose sum is σ = 21212102102. Its totient is φ = 21212102100.

The previous prime is 21212102039. The next prime is 21212102141. The reversal of 21212102101 is 10120121212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19320722001 + 1891380100 = 138999^2 + 43490^2 .

It is a cyclic number.

It is not a de Polignac number, because 21212102101 - 2⁷ = 21212101973 is a prime.

It is a super-3 number, since 3×21212102101³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21212102141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606051050 + 10606051051.

It is an arithmetic number, because the mean of its divisors is an integer number (10606051051).

Almost surely, 2^21212102101 is an apocalyptic number.

It is an amenable number.

21212102101 is a deficient number, since it is larger than the sum of its proper divisors (1).

21212102101 is an equidigital number, since it uses as much as digits as its factorization.

21212102101 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 21212102101 its reverse (10120121212), we get a palindrome (31332223313).

The spelling of 21212102101 in words is "twenty-one billion, two hundred twelve million, one hundred two thousand, one hundred one".