21210111010220 has 96 divisors (see below), whose sum is σ = 48773761727040. Its totient is φ = 7683696783360.

The previous prime is 21210111010199. The next prime is 21210111010237. The reversal of 21210111010220 is 2201011101212.

It is a junction number, because it is equal to n+sod(n) for n = 21210111010195 and 21210111010204.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 120623726 + ... + 120799434.

It is an arithmetic number, because the mean of its divisors is an integer number (508060017990).

Almost surely, 2^{21210111010220} is an apocalyptic number.

21210111010220 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 21210111010220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24386880863520).

21210111010220 is an abundant number, since it is smaller than the sum of its proper divisors (27563650716820).

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

21210111010220 is a wasteful number, since it uses less digits than its factorization.

21210111010220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 177795 (or 177793 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 21210111010220 its reverse (2201011101212), we get a palindrome (23411122111432).

The spelling of 21210111010220 in words is "twenty-one trillion, two hundred ten billion, one hundred eleven million, ten thousand, two hundred twenty".