21330000 has 200 divisors, whose sum is σ = 77475200. Its totient is φ = 5616000.

The previous prime is 21329999. The next prime is 21330047. The reversal of 21330000 is 3312.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (200).

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 269961 + ... + 270039.

It is an arithmetic number, because the mean of its divisors is an integer number (387376).

Almost surely, 2^21330000 is an apocalyptic number.

21330000 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 21330000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38737600).

21330000 is an abundant number, since it is smaller than the sum of its proper divisors (56145200).

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

21330000 is an equidigital number, since it uses as much as digits as its factorization.

21330000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116 (or 89 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 9.

The square root of 21330000 is about 4618.4412955022. The cubic root of 21330000 is about 277.3300639613.

Adding to 21330000 its reverse (3312), we get a palindrome (21333312).

The spelling of 21330000 in words is "twenty-one million, three hundred thirty thousand".