21221212112212 has 192 divisors, whose sum is σ = 45983171211264. Its totient is φ = 8363408025600.

The previous prime is 21221212112201. The next prime is 21221212112239. The reversal of 21221212112212 is 21221121212212.

It is a super-2 number, since 2×21221212112212² (a number of 27 digits) contains 22 as substring.

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

It is a congruent number.

It is an unprimeable number.

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, 4241694903 + ... + 4241699905.

It is an arithmetic number, because the mean of its divisors is an integer number (239495683392).

Almost surely, 2^{21221212112212} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21221212112212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22991585605632).

21221212112212 is an abundant number, since it is smaller than the sum of its proper divisors (24761959099052).

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

21221212112212 is a wasteful number, since it uses less digits than its factorization.

21221212112212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6278 (or 6276 counting only the distinct ones).

The product of its digits is 256, while the sum is 22.

Adding to 21221212112212 its reverse (21221121212212), we get a palindrome (42442333324424).

The spelling of 21221212112212 in words is "twenty-one trillion, two hundred twenty-one billion, two hundred twelve million, one hundred twelve thousand, two hundred twelve".