21330300 has 72 divisors (see below), whose sum is σ = 62436976. Its totient is φ = 5621760.

The previous prime is 21330299. The next prime is 21330311. The reversal of 21330300 is 303312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is a congruent number.

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, 28734 + ... + 29466.

Almost surely, 2^21330300 is an apocalyptic number.

21330300 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 21330300, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31218488).

21330300 is an abundant number, since it is smaller than the sum of its proper divisors (41106676).

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

21330300 is a wasteful number, since it uses less digits than its factorization.

21330300 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 847 (or 840 counting only the distinct ones).

The product of its (nonzero) digits is 54, while the sum is 12.

The square root of 21330300 is about 4618.4737738781. The cubic root of 21330300 is about 277.3313641430.

Subtracting from 21330300 its product of nonzero digits (54), we obtain a triangular number (21330246 = T₆₅₃₁).

Adding to 21330300 its reverse (303312), we get a palindrome (21633612).

The spelling of 21330300 in words is "twenty-one million, three hundred thirty thousand, three hundred".