21222011121220 has 192 divisors, whose sum is σ = 56009534515200. Its totient is φ = 6711689327616.

The previous prime is 21222011121211. The next prime is 21222011121221. The reversal of 21222011121220 is 2212111022212.

It is not an unprimeable number, because it can be changed into a prime (21222011121221) 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, 127711909 + ... + 127877971.

It is an arithmetic number, because the mean of its divisors is an integer number (291716325600).

Almost surely, 2^{21222011121220} is an apocalyptic number.

21222011121220 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 21222011121220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28004767257600).

21222011121220 is an abundant number, since it is smaller than the sum of its proper divisors (34787523393980).

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

21222011121220 is a wasteful number, since it uses less digits than its factorization.

21222011121220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167539 (or 167523 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21222011121220 its reverse (2212111022212), we get a palindrome (23434122143432).

The spelling of 21222011121220 in words is "twenty-one trillion, two hundred twenty-two billion, eleven million, one hundred twenty-one thousand, two hundred twenty".