21221222212212 has 192 divisors, whose sum is σ = 56113527230208. Its totient is φ = 6185341440000.

The previous prime is 21221222212193. The next prime is 21221222212217.

It is a happy number.

21221222212212 is nontrivially palindromic in base 10.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221222212217) 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 63 ways as a sum of consecutive naturals, for example, 322081512 + ... + 322147392.

It is an arithmetic number, because the mean of its divisors is an integer number (292257954324).

Almost surely, 2^{21221222212212} is an apocalyptic number.

21221222212212 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21221222212212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28056763615104).

21221222212212 is an abundant number, since it is smaller than the sum of its proper divisors (34892305017996).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21221222212212 is a wasteful number, since it uses less digits than its factorization.

21221222212212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66690 (or 66688 counting only the distinct ones).

The product of its digits is 1024, while the sum is 24.

It can be divided in two parts, 2122122 and 2212212, that added together give a palindrome (4334334).

The spelling of 21221222212212 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twenty-two million, two hundred twelve thousand, two hundred twelve".