21122210011221 has 72 divisors (see below), whose sum is σ = 34731542506752. Its totient is φ = 12352503979200.

The previous prime is 21122210011181. The next prime is 21122210011223. The reversal of 21122210011221 is 12211001222112.

21122210011221 is a `hidden beast` number, since 211 + 2 + 221 + 0 + 0 + 11 + 221 = 666.

It is not a de Polignac number, because 21122210011221 - 2¹⁹ = 21122209486933 is a prime.

It is a super-2 number, since 2×21122210011221² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21122210011194 and 21122210011203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21122210011223) 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 71 ways as a sum of consecutive naturals, for example, 727795 + ... + 6540191.

It is an arithmetic number, because the mean of its divisors is an integer number (482382534816).

Almost surely, 2^{21122210011221} is an apocalyptic number.

It is an amenable number.

21122210011221 is a deficient number, since it is larger than the sum of its proper divisors (13609332495531).

21122210011221 is a wasteful number, since it uses less digits than its factorization.

21122210011221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5812543 (or 5812529 counting only the distinct ones).

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

Adding to 21122210011221 its reverse (12211001222112), we get a palindrome (33333211233333).

The spelling of 21122210011221 in words is "twenty-one trillion, one hundred twenty-two billion, two hundred ten million, eleven thousand, two hundred twenty-one".