21212201010220 has 192 divisors, whose sum is σ = 51927203091456. Its totient is φ = 7202182507520.

The previous prime is 21212201010173. The next prime is 21212201010229. The reversal of 21212201010220 is 2201010221212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21212201010194 and 21212201010203.

It is not an unprimeable number, because it can be changed into a prime (21212201010229) 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, 52630707 + ... + 53032213.

It is an arithmetic number, because the mean of its divisors is an integer number (270454182768).

Almost surely, 2^{21212201010220} is an apocalyptic number.

21212201010220 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 21212201010220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25963601545728).

21212201010220 is an abundant number, since it is smaller than the sum of its proper divisors (30715002081236).

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

21212201010220 is a wasteful number, since it uses less digits than its factorization.

21212201010220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 401800 (or 401798 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21212201010220 its reverse (2201010221212), we get a palindrome (23413211231432).

The spelling of 21212201010220 in words is "twenty-one trillion, two hundred twelve billion, two hundred one million, ten thousand, two hundred twenty".