21220112320 has 112 divisors (see below), whose sum is σ = 55218787200. Its totient is φ = 7703147520.

The previous prime is 21220112299. The next prime is 21220112327. The reversal of 21220112320 is 2321102212.

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 = 21220112294 and 21220112303.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21220112327) 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, 2174011 + ... + 2183749.

Almost surely, 2^21220112320 is an apocalyptic number.

21220112320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21220112320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27609393600).

21220112320 is an abundant number, since it is smaller than the sum of its proper divisors (33998674880).

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

21220112320 is a wasteful number, since it uses less digits than its factorization.

21220112320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10386 (or 10376 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21220112320 its reverse (2321102212), we get a palindrome (23541214532).

The spelling of 21220112320 in words is "twenty-one billion, two hundred twenty million, one hundred twelve thousand, three hundred twenty".