21020332320 has 576 divisors, whose sum is σ = 82191957120. Its totient is φ = 4849238016.

The previous prime is 21020332309. The next prime is 21020332331. The reversal of 21020332320 is 2323302012.

It is a happy number.

21020332320 is a `hidden beast` number, since 2 + 10 + 2 + 0 + 332 + 320 = 666.

It is an interprime number because it is at equal distance from previous prime (21020332309) and next prime (21020332331).

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 = 21020332293 and 21020332302.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 40191579 + ... + 40192101.

It is an arithmetic number, because the mean of its divisors is an integer number (142694370).

Almost surely, 2^21020332320 is an apocalyptic number.

21020332320 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 21020332320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41095978560).

21020332320 is an abundant number, since it is smaller than the sum of its proper divisors (61171624800).

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

21020332320 is a wasteful number, since it uses less digits than its factorization.

21020332320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 689 (or 678 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 18.

Adding to 21020332320 its reverse (2323302012), we get a palindrome (23343634332).

The spelling of 21020332320 in words is "twenty-one billion, twenty million, three hundred thirty-two thousand, three hundred twenty".