21221200112 has 80 divisors (see below), whose sum is σ = 48043115520. Its totient is φ = 8891368704.

The previous prime is 21221200069. The next prime is 21221200157. The reversal of 21221200112 is 21100212212.

It is a Harshad number since it is a multiple of its sum of digits (14).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6509939 + ... + 6513197.

It is an arithmetic number, because the mean of its divisors is an integer number (600538944).

Almost surely, 2^21221200112 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 21221200112, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24021557760).

21221200112 is an abundant number, since it is smaller than the sum of its proper divisors (26821915408).

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

21221200112 is a wasteful number, since it uses less digits than its factorization.

21221200112 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4558 (or 4552 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21221200112 its reverse (21100212212), we get a palindrome (42321412324).

The spelling of 21221200112 in words is "twenty-one billion, two hundred twenty-one million, two hundred thousand, one hundred twelve".