21210110220220 has 24 divisors (see below), whose sum is σ = 44619511330800. Its totient is φ = 8469133636992.

The previous prime is 21210110220199. The next prime is 21210110220259. The reversal of 21210110220220 is 2202201101212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21210110220194 and 21210110220203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 931891530 + ... + 931914289.

It is an arithmetic number, because the mean of its divisors is an integer number (1859146305450).

Almost surely, 2^{21210110220220} is an apocalyptic number.

21210110220220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21210110220220 is an abundant number, since it is smaller than the sum of its proper divisors (23409401110580).

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

21210110220220 is a wasteful number, since it uses less digits than its factorization.

21210110220220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1863806397 (or 1863806395 counting only the distinct ones).

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

Adding to 21210110220220 its reverse (2202201101212), we get a palindrome (23412311321432).

The spelling of 21210110220220 in words is "twenty-one trillion, two hundred ten billion, one hundred ten million, two hundred twenty thousand, two hundred twenty".