21222002320 has 80 divisors (see below), whose sum is σ = 50973880320. Its totient is φ = 8208345600.

The previous prime is 21222002303. The next prime is 21222002323. The reversal of 21222002320 is 2320022212.

It is a tau number, because it is divible by the number of its divisors (80).

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 = 21222002294 and 21222002303.

It is not an unprimeable number, because it can be changed into a prime (21222002323) 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, 4017441 + ... + 4022719.

It is an arithmetic number, because the mean of its divisors is an integer number (637173504).

Almost surely, 2^21222002320 is an apocalyptic number.

21222002320 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 21222002320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25486940160).

21222002320 is an abundant number, since it is smaller than the sum of its proper divisors (29751878000).

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

21222002320 is a wasteful number, since it uses less digits than its factorization.

21222002320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6944 (or 6938 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

Adding to 21222002320 its reverse (2320022212), we get a palindrome (23542024532).

The spelling of 21222002320 in words is "twenty-one billion, two hundred twenty-two million, two thousand, three hundred twenty".