21002303220 has 48 divisors (see below), whose sum is σ = 61901528640. Its totient is φ = 5305844736.

The previous prime is 21002303209. The next prime is 21002303227. The reversal of 21002303220 is 2230320012.

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 21002303220.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002303227) 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, 9210397 + ... + 9212676.

It is an arithmetic number, because the mean of its divisors is an integer number (1289615180).

Almost surely, 2^21002303220 is an apocalyptic number.

21002303220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21002303220 is an abundant number, since it is smaller than the sum of its proper divisors (40899225420).

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

21002303220 is a wasteful number, since it uses less digits than its factorization.

21002303220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18423104 (or 18423102 counting only the distinct ones).

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

Adding to 21002303220 its reverse (2230320012), we get a palindrome (23232623232).

The spelling of 21002303220 in words is "twenty-one billion, two million, three hundred three thousand, two hundred twenty".