21222120111020 has 12 divisors (see below), whose sum is σ = 44566452233184. Its totient is φ = 8488848044400.

The previous prime is 21222120111011. The next prime is 21222120111029. The reversal of 21222120111020 is 2011102122212.

It is an interprime number because it is at equal distance from previous prime (21222120111011) and next prime (21222120111029).

It is a self number, because there is not a number n which added to its sum of digits gives 21222120111020.

It is not an unprimeable number, because it can be changed into a prime (21222120111029) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 530553002756 + ... + 530553002795.

It is an arithmetic number, because the mean of its divisors is an integer number (3713871019432).

Almost surely, 2^{21222120111020} is an apocalyptic number.

21222120111020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21222120111020 is an abundant number, since it is smaller than the sum of its proper divisors (23344332122164).

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

21222120111020 is a wasteful number, since it uses less digits than its factorization.

21222120111020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1061106005560 (or 1061106005558 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21222120111020 its reverse (2011102122212), we get a palindrome (23233222233232).

The spelling of 21222120111020 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred twenty million, one hundred eleven thousand, twenty".