21220221000000 has 784 divisors, whose sum is σ = 76758611227200. Its totient is φ = 5131008000000.

The previous prime is 21220220999959. The next prime is 21220221000001. The reversal of 21220221000000 is 12202212.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a self number, because there is not a number n which added to its sum of digits gives 21220221000000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220221000001) by changing a digit.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 20228999476 + ... + 20229000524.

Almost surely, 2^{21220221000000} is an apocalyptic number.

21220221000000 is a gapful number since it is divisible by the number (20) 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 21220221000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38379305613600).

21220221000000 is an abundant number, since it is smaller than the sum of its proper divisors (55538390227200).

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

21220221000000 is an equidigital number, since it uses as much as digits as its factorization.

21220221000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1718 (or 1683 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 12.

Adding to 21220221000000 its reverse (12202212), we get a palindrome (21220233202212).

The spelling of 21220221000000 in words is "twenty-one trillion, two hundred twenty billion, two hundred twenty-one million", and thus it is an aban number.