21011203320 has 128 divisors (see below), whose sum is σ = 64801175040. Its totient is φ = 5446172160.

The previous prime is 21011203307. The next prime is 21011203361. The reversal of 21011203320 is 2330211012.

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 21011203320.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 6582925 + ... + 6586115.

It is an arithmetic number, because the mean of its divisors is an integer number (506259180).

Almost surely, 2^21011203320 is an apocalyptic number.

21011203320 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 21011203320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32400587520).

21011203320 is an abundant number, since it is smaller than the sum of its proper divisors (43789971720).

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

21011203320 is a wasteful number, since it uses less digits than its factorization.

21011203320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4725 (or 4721 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21011203320 its reverse (2330211012), we get a palindrome (23341414332).

The spelling of 21011203320 in words is "twenty-one billion, eleven million, two hundred three thousand, three hundred twenty".