21330331220 has 24 divisors (see below), whose sum is σ = 48865850208. Its totient is φ = 7756484000.

The previous prime is 21330331201. The next prime is 21330331369. The reversal of 21330331220 is 2213303312.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21330331192 and 21330331201.

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 7 ways as a sum of consecutive naturals, for example, 48477806 + ... + 48478245.

It is an arithmetic number, because the mean of its divisors is an integer number (2036077092).

Almost surely, 2^21330331220 is an apocalyptic number.

21330331220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21330331220 is an abundant number, since it is smaller than the sum of its proper divisors (27535518988).

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

21330331220 is a wasteful number, since it uses less digits than its factorization.

21330331220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96956071 (or 96956069 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 20.

Adding to 21330331220 its reverse (2213303312), we get a palindrome (23543634532).

The spelling of 21330331220 in words is "twenty-one billion, three hundred thirty million, three hundred thirty-one thousand, two hundred twenty".