21221122211212 has 192 divisors, whose sum is σ = 48445476323328. Its totient is φ = 7886954592000.

The previous prime is 21221122211173. The next prime is 21221122211213. The reversal of 21221122211212 is 21211222112212.

It is a super-3 number, since 3×21221122211212³ (a number of 41 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (22).

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

It is not an unprimeable number, because it can be changed into a prime (21221122211213) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4832865537 + ... + 4832869927.

It is an arithmetic number, because the mean of its divisors is an integer number (252320189184).

Almost surely, 2^{21221122211212} is an apocalyptic number.

21221122211212 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 21221122211212, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24222738161664).

21221122211212 is an abundant number, since it is smaller than the sum of its proper divisors (27224354112116).

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

21221122211212 is a wasteful number, since it uses less digits than its factorization.

21221122211212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6140 (or 6138 counting only the distinct ones).

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

Adding to 21221122211212 its reverse (21211222112212), we get a palindrome (42432344323424).

The spelling of 21221122211212 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred twenty-two million, two hundred eleven thousand, two hundred twelve".