21330311220 has 72 divisors (see below), whose sum is σ = 64753075296. Its totient is φ = 5683588032.

The previous prime is 21330311161. The next prime is 21330311231. The reversal of 21330311220 is 2211303312.

21330311220 is a `hidden beast` number, since 2 + 1 + 330 + 311 + 2 + 20 = 666.

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 = 21330311193 and 21330311202.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 184759 + ... + 277121.

It is an arithmetic number, because the mean of its divisors is an integer number (899348268).

Almost surely, 2^21330311220 is an apocalyptic number.

21330311220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21330311220 is an abundant number, since it is smaller than the sum of its proper divisors (43422764076).

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

21330311220 is a wasteful number, since it uses less digits than its factorization.

21330311220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93661 (or 93656 counting only the distinct ones).

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

Adding to 21330311220 its reverse (2211303312), we get a palindrome (23541614532).

The spelling of 21330311220 in words is "twenty-one billion, three hundred thirty million, three hundred eleven thousand, two hundred twenty".