21222012210021 has 40 divisors (see below), whose sum is σ = 38362106122560. Its totient is φ = 11413519166592.

The previous prime is 21222012209999. The next prime is 21222012210029. The reversal of 21222012210021 is 12001221022212.

It is a happy number.

21222012210021 is a `hidden beast` number, since 212 + 220 + 1 + 2 + 210 + 0 + 21 = 666.

It is not a de Polignac number, because 21222012210021 - 2¹⁵ = 21222012177253 is a prime.

It is a super-2 number, since 2×21222012210021² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21222012209976 and 21222012210003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222012210029) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1100831331 + ... + 1100850608.

It is an arithmetic number, because the mean of its divisors is an integer number (959052653064).

Almost surely, 2^{21222012210021} is an apocalyptic number.

21222012210021 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

21222012210021 is a deficient number, since it is larger than the sum of its proper divisors (17140093912539).

21222012210021 is a wasteful number, since it uses less digits than its factorization.

21222012210021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2201681975 (or 2201681966 counting only the distinct ones).

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

Adding to 21222012210021 its reverse (12001221022212), we get a palindrome (33223233232233).

The spelling of 21222012210021 in words is "twenty-one trillion, two hundred twenty-two billion, twelve million, two hundred ten thousand, twenty-one".