21100221120210 has 128 divisors (see below), whose sum is σ = 53322403921920. Its totient is φ = 5333359680000.

The previous prime is 21100221120157. The next prime is 21100221120211. The reversal of 21100221120210 is 1202112200112.

It is a super-2 number, since 2×21100221120210² (a number of 27 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21100221120210.

It is not an unprimeable number, because it can be changed into a prime (21100221120211) 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, 42366135 + ... + 42861285.

It is an arithmetic number, because the mean of its divisors is an integer number (416581280640).

Almost surely, 2^{21100221120210} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21100221120210, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26661201960960).

21100221120210 is an abundant number, since it is smaller than the sum of its proper divisors (32222182801710).

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

21100221120210 is a wasteful number, since it uses less digits than its factorization.

21100221120210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 495744.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21100221120210 its reverse (1202112200112), we get a palindrome (22302333320322).

The spelling of 21100221120210 in words is "twenty-one trillion, one hundred billion, two hundred twenty-one million, one hundred twenty thousand, two hundred ten".