21120334020 has 144 divisors (see below), whose sum is σ = 66412710000. Its totient is φ = 5426512896.

The previous prime is 21120333989. The next prime is 21120334021. The reversal of 21120334020 is 2043302112.

21120334020 is a `hidden beast` number, since 211 + 20 + 33 + 402 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 209438784 + 20910895236 = 14472^2 + 144606^2 .

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 = 21120333984 and 21120334002.

It is not an unprimeable number, because it can be changed into a prime (21120334021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2653006 + ... + 2660954.

It is an arithmetic number, because the mean of its divisors is an integer number (461199375).

Almost surely, 2^21120334020 is an apocalyptic number.

21120334020 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 21120334020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33206355000).

21120334020 is an abundant number, since it is smaller than the sum of its proper divisors (45292375980).

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

21120334020 is a wasteful number, since it uses less digits than its factorization.

21120334020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8502 (or 8497 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21120334020 its reverse (2043302112), we get a palindrome (23163636132).

The spelling of 21120334020 in words is "twenty-one billion, one hundred twenty million, three hundred thirty-four thousand, twenty".