21221333210220 has 384 divisors, whose sum is σ = 70460692162560. Its totient is φ = 4704457605120.

The previous prime is 21221333210159. The next prime is 21221333210227. The reversal of 21221333210220 is 2201233312212.

It is not an unprimeable number, because it can be changed into a prime (21221333210227) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2566368246 + ... + 2566376514.

It is an arithmetic number, because the mean of its divisors is an integer number (183491385840).

Almost surely, 2^{21221333210220} is an apocalyptic number.

21221333210220 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 21221333210220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35230346081280).

21221333210220 is an abundant number, since it is smaller than the sum of its proper divisors (49239358952340).

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

21221333210220 is a wasteful number, since it uses less digits than its factorization.

21221333210220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11065 (or 11063 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 24.

Adding to 21221333210220 its reverse (2201233312212), we get a palindrome (23422566522432).

It can be divided in two parts, 212213 and 33210220, that added together give a palindrome (33422433).

The spelling of 21221333210220 in words is "twenty-one trillion, two hundred twenty-one billion, three hundred thirty-three million, two hundred ten thousand, two hundred twenty".