21212102211021 has 128 divisors (see below), whose sum is σ = 34494356736000. Its totient is φ = 12839613253632.

The previous prime is 21212102210993. The next prime is 21212102211023. The reversal of 21212102211021 is 12011220121212.

21212102211021 is a `hidden beast` number, since 212 + 1 + 210 + 221 + 1 + 0 + 21 = 666.

It is not a de Polignac number, because 21212102211021 - 2⁴³ = 12416009188813 is a prime.

It is a super-3 number, since 3×21212102211021³ (a number of 41 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21212102210985 and 21212102211003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212102211023) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 196651315 + ... + 196759151.

It is an arithmetic number, because the mean of its divisors is an integer number (269487162000).

Almost surely, 2^{21212102211021} is an apocalyptic number.

It is an amenable number.

21212102211021 is a deficient number, since it is larger than the sum of its proper divisors (13282254524979).

21212102211021 is a wasteful number, since it uses less digits than its factorization.

21212102211021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108088 (or 108082 counting only the distinct ones).

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

Adding to 21212102211021 its reverse (12011220121212), we get a palindrome (33223322332233).

The spelling of 21212102211021 in words is "twenty-one trillion, two hundred twelve billion, one hundred two million, two hundred eleven thousand, twenty-one".