21212221120 has 28 divisors (see below), whose sum is σ = 50511602304. Its totient is φ = 8484888320.

The previous prime is 21212221117. The next prime is 21212221133. The reversal of 21212221120 is 2112221212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (16).

It is a junction number, because it is equal to n+sod(n) for n = 21212221094 and 21212221103.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 33143776 + ... + 33144415.

Almost surely, 2^21212221120 is an apocalyptic number.

21212221120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21212221120 is an abundant number, since it is smaller than the sum of its proper divisors (29299381184).

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

21212221120 is an equidigital number, since it uses as much as digits as its factorization.

21212221120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66288208 (or 66288198 counting only the distinct ones).

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

Adding to 21212221120 its reverse (2112221212), we get a palindrome (23324442332).

The spelling of 21212221120 in words is "twenty-one billion, two hundred twelve million, two hundred twenty-one thousand, one hundred twenty".