21210112202220 has 144 divisors (see below), whose sum is σ = 64779332567040. Its totient is φ = 5617191888000.

The previous prime is 21210112202219. The next prime is 21210112202221. The reversal of 21210112202220 is 2220221101212.

It is a happy number.

21210112202220 is a `hidden beast` number, since 2 + 1 + 210 + 11 + 220 + 2 + 220 = 666.

It is an interprime number because it is at equal distance from previous prime (21210112202219) and next prime (21210112202221).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21210112202193 and 21210112202202.

It is not an unprimeable number, because it can be changed into a prime (21210112202221) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 112947805 + ... + 113135435.

It is an arithmetic number, because the mean of its divisors is an integer number (449856476160).

Almost surely, 2^{21210112202220} is an apocalyptic number.

21210112202220 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 21210112202220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32389666283520).

21210112202220 is an abundant number, since it is smaller than the sum of its proper divisors (43569220364820).

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

21210112202220 is a wasteful number, since it uses less digits than its factorization.

21210112202220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191956 (or 191951 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 21210112202220 its reverse (2220221101212), we get a palindrome (23430333303432).

The spelling of 21210112202220 in words is "twenty-one trillion, two hundred ten billion, one hundred twelve million, two hundred two thousand, two hundred twenty".