21220300320 has 192 divisors, whose sum is σ = 70910090496. Its totient is φ = 5315788800.

The previous prime is 21220300307. The next prime is 21220300357. The reversal of 21220300320 is 2300302212.

It is a super-2 number, since 2×21220300320² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 21220300320.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4901997 + ... + 4906323.

It is an arithmetic number, because the mean of its divisors is an integer number (369323388).

Almost surely, 2^21220300320 is an apocalyptic number.

21220300320 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 21220300320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35455045248).

21220300320 is an abundant number, since it is smaller than the sum of its proper divisors (49689790176).

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

21220300320 is a wasteful number, since it uses less digits than its factorization.

21220300320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4963 (or 4955 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 15.

Adding to 21220300320 its reverse (2300302212), we get a palindrome (23520602532).

The spelling of 21220300320 in words is "twenty-one billion, two hundred twenty million, three hundred thousand, three hundred twenty".