21221120112 has 80 divisors (see below), whose sum is σ = 55785774720. Its totient is φ = 6949806336.

The previous prime is 21221120093. The next prime is 21221120113. The reversal of 21221120112 is 21102112212.

It is a junction number, because it is equal to n+sod(n) for n = 21221120091 and 21221120100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221120113) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1242543 + ... + 1259505.

It is an arithmetic number, because the mean of its divisors is an integer number (697322184).

Almost surely, 2^21221120112 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21221120112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27892887360).

21221120112 is an abundant number, since it is smaller than the sum of its proper divisors (34564654608).

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

21221120112 is a wasteful number, since it uses less digits than its factorization.

21221120112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17430 (or 17424 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 21221120112 its reverse (21102112212), we get a palindrome (42323232324).

The spelling of 21221120112 in words is "twenty-one billion, two hundred twenty-one million, one hundred twenty thousand, one hundred twelve".