21232120320 has 480 divisors, whose sum is σ = 77942779200. Its totient is φ = 5332303872.

The previous prime is 21232120309. The next prime is 21232120333. The reversal of 21232120320 is 2302123212.

21232120320 is a `hidden beast` number, since 2 + 1 + 2 + 321 + 20 + 320 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

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 = 21232120293 and 21232120302.

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, 28730511 + ... + 28731249.

It is an arithmetic number, because the mean of its divisors is an integer number (162380790).

Almost surely, 2^21232120320 is an apocalyptic number.

21232120320 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 21232120320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38971389600).

21232120320 is an abundant number, since it is smaller than the sum of its proper divisors (56710658880).

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

21232120320 is a wasteful number, since it uses less digits than its factorization.

21232120320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 840 (or 821 counting only the distinct ones).

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

Adding to 21232120320 its reverse (2302123212), we get a palindrome (23534243532).

The spelling of 21232120320 in words is "twenty-one billion, two hundred thirty-two million, one hundred twenty thousand, three hundred twenty".