21331013220 has 144 divisors (see below), whose sum is σ = 73020467520. Its totient is φ = 4992825600.

The previous prime is 21331013213. The next prime is 21331013239. The reversal of 21331013220 is 2231013312.

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 = 21331013193 and 21331013202.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 128326 + ... + 243165.

It is an arithmetic number, because the mean of its divisors is an integer number (507086580).

Almost surely, 2^21331013220 is an apocalyptic number.

21331013220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21331013220 is an abundant number, since it is smaller than the sum of its proper divisors (51689454300).

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

21331013220 is a wasteful number, since it uses less digits than its factorization.

21331013220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371546 (or 371541 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21331013220 its reverse (2231013312), we get a palindrome (23562026532).

The spelling of 21331013220 in words is "twenty-one billion, three hundred thirty-one million, thirteen thousand, two hundred twenty".