21012333320 has 128 divisors (see below), whose sum is σ = 54366249600. Its totient is φ = 7228569600.

The previous prime is 21012333311. The next prime is 21012333361. The reversal of 21012333320 is 2333321012.

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 = 21012333292 and 21012333301.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8333660 + ... + 8336180.

It is an arithmetic number, because the mean of its divisors is an integer number (424736325).

Almost surely, 2^21012333320 is an apocalyptic number.

21012333320 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 21012333320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27183124800).

21012333320 is an abundant number, since it is smaller than the sum of its proper divisors (33353916280).

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

21012333320 is a wasteful number, since it uses less digits than its factorization.

21012333320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3559 (or 3555 counting only the distinct ones).

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

Adding to 21012333320 its reverse (2333321012), we get a palindrome (23345654332).

The spelling of 21012333320 in words is "twenty-one billion, twelve million, three hundred thirty-three thousand, three hundred twenty".