21212110212021 has 24 divisors (see below), whose sum is σ = 31206887712000. Its totient is φ = 13881920893632.

The previous prime is 21212110212019. The next prime is 21212110212043. The reversal of 21212110212021 is 12021201121212.

It is not a de Polignac number, because 21212110212021 - 2¹ = 21212110212019 is a prime.

It is a super-3 number, since 3×21212110212021³ (a number of 41 digits) contains 333 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21212110211985 and 21212110212003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212110212221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 95147781 + ... + 95370458.

It is an arithmetic number, because the mean of its divisors is an integer number (1300286988000).

Almost surely, 2^{21212110212021} is an apocalyptic number.

It is an amenable number.

21212110212021 is a deficient number, since it is larger than the sum of its proper divisors (9994777499979).

21212110212021 is a wasteful number, since it uses less digits than its factorization.

21212110212021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 190518473 (or 190518470 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 21212110212021 its reverse (12021201121212), we get a palindrome (33233311333233).

The spelling of 21212110212021 in words is "twenty-one trillion, two hundred twelve billion, one hundred ten million, two hundred twelve thousand, twenty-one".