21030336 has 84 divisors (see below), whose sum is σ = 62407800. Its totient is φ = 6763008.

The previous prime is 21030329. The next prime is 21030337. The reversal of 21030336 is 63303012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21030337) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16075 + ... + 17333.

It is an arithmetic number, because the mean of its divisors is an integer number (742950).

Almost surely, 2^21030336 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21030336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31203900).

21030336 is an abundant number, since it is smaller than the sum of its proper divisors (41377464).

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

21030336 is a wasteful number, since it uses less digits than its factorization.

21030336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1306 (or 1293 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 18.

The square root of 21030336 is about 4585.8844294203. The cubic root of 21030336 is about 276.0252024875.

Adding to 21030336 its reverse (63303012), we get a palindrome (84333348).

The spelling of 21030336 in words is "twenty-one million, thirty thousand, three hundred thirty-six".