21102212202021 has 12 divisors (see below), whose sum is σ = 30481039560972. Its totient is φ = 14068110830976.

The previous prime is 21102212202017. The next prime is 21102212202041. The reversal of 21102212202021 is 12020221220112.

It is a happy number.

21102212202021 is a `hidden beast` number, since 21 + 1 + 0 + 221 + 220 + 202 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 18787283424900 + 2314928777121 = 4334430^2 + 1521489^2 .

It is not a de Polignac number, because 21102212202021 - 2² = 21102212202017 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21102212201985 and 21102212202003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102212202041) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2293405 + ... + 6889421.

It is an arithmetic number, because the mean of its divisors is an integer number (2540086630081).

Almost surely, 2^{21102212202021} is an apocalyptic number.

It is an amenable number.

21102212202021 is a deficient number, since it is larger than the sum of its proper divisors (9378827358951).

21102212202021 is a wasteful number, since it uses less digits than its factorization.

21102212202021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5106180 (or 5106177 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21102212202021 its reverse (12020221220112), we get a palindrome (33122433422133).

The spelling of 21102212202021 in words is "twenty-one trillion, one hundred two billion, two hundred twelve million, two hundred two thousand, twenty-one".