21203320320 has 640 divisors, whose sum is σ = 92724065280. Its totient is φ = 4472340480.

The previous prime is 21203320319. The next prime is 21203320321. The reversal of 21203320320 is 2302330212.

It is a happy number.

21203320320 is a `hidden beast` number, since 2 + 1 + 20 + 3 + 320 + 320 = 666.

It is an interprime number because it is at equal distance from previous prime (21203320319) and next prime (21203320321).

It is a tau number, because it is divible by the number of its divisors (640).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21203320293 and 21203320302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21203320321) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6288235 + ... + 6291605.

It is an arithmetic number, because the mean of its divisors is an integer number (144881352).

Almost surely, 2^21203320320 is an apocalyptic number.

21203320320 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 21203320320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46362032640).

21203320320 is an abundant number, since it is smaller than the sum of its proper divisors (71520744960).

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

21203320320 is a wasteful number, since it uses less digits than its factorization.

21203320320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3423 (or 3401 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 18.

Adding to 21203320320 its reverse (2302330212), we get a palindrome (23505650532).

The spelling of 21203320320 in words is "twenty-one billion, two hundred three million, three hundred twenty thousand, three hundred twenty".