21223213320 has 128 divisors (see below), whose sum is σ = 66499574400. Its totient is φ = 5413165056.

The previous prime is 21223213307. The next prime is 21223213373. The reversal of 21223213320 is 2331232212.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 221452 + ... + 302468.

It is an arithmetic number, because the mean of its divisors is an integer number (519527925).

Almost surely, 2^21223213320 is an apocalyptic number.

21223213320 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 21223213320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33249787200).

21223213320 is an abundant number, since it is smaller than the sum of its proper divisors (45276361080).

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

21223213320 is a wasteful number, since it uses less digits than its factorization.

21223213320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81127 (or 81123 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 21223213320 its reverse (2331232212), we get a palindrome (23554445532).

The spelling of 21223213320 in words is "twenty-one billion, two hundred twenty-three million, two hundred thirteen thousand, three hundred twenty".