21325320 has 96 divisors (see below), whose sum is σ = 71224920. Its totient is φ = 5529600.

The previous prime is 21325319. The next prime is 21325331. The reversal of 21325320 is 2352312.

21325320 is a `hidden beast` number, since 2 + 132 + 532 + 0 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 20958084 + 367236 = 4578^2 + 606^2 .

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 = 21325293 and 21325302.

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, 12520 + ... + 14120.

Almost surely, 2^21325320 is an apocalyptic number.

21325320 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 21325320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35612460).

21325320 is an abundant number, since it is smaller than the sum of its proper divisors (49899600).

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

21325320 is a wasteful number, since it uses less digits than its factorization.

21325320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1655 (or 1648 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 21325320 is about 4617.9346032615. The cubic root of 21325320 is about 277.3097795476.

Adding to 21325320 its reverse (2352312), we get a palindrome (23677632).

The spelling of 21325320 in words is "twenty-one million, three hundred twenty-five thousand, three hundred twenty".