21222120021210 has 64 divisors (see below), whose sum is σ = 57152640130560. Its totient is φ = 5603199998400.

The previous prime is 21222120021187. The next prime is 21222120021217. The reversal of 21222120021210 is 1212002122212.

It is a happy number.

21222120021210 is a `hidden beast` number, since 2 + 12 + 221 + 200 + 21 + 210 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (21222120021217) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 389083842 + ... + 389138381.

It is an arithmetic number, because the mean of its divisors is an integer number (893010002040).

Almost surely, 2^{21222120021210} is an apocalyptic number.

21222120021210 is an abundant number, since it is smaller than the sum of its proper divisors (35930520109350).

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

21222120021210 is a wasteful number, since it uses less digits than its factorization.

21222120021210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 778222340 (or 778222334 counting only the distinct ones).

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

Adding to 21222120021210 its reverse (1212002122212), we get a palindrome (22434122143422).

The spelling of 21222120021210 in words is "twenty-one trillion, two hundred twenty-two billion, one hundred twenty million, twenty-one thousand, two hundred ten".