21363264 has 140 divisors (see below), whose sum is σ = 68413884. Its totient is φ = 6552576.

The previous prime is 21363257. The next prime is 21363289. The reversal of 21363264 is 46236312.

21363264 is a `hidden beast` number, since 21 + 3 + 632 + 6 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 2073600 + 19289664 = 1440^2 + 4392^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 67234 + ... + 67550.

Almost surely, 2^21363264 is an apocalyptic number.

21363264 is a gapful number since it is divisible by the number (24) 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 21363264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34206942).

21363264 is an abundant number, since it is smaller than the sum of its proper divisors (47050620).

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

21363264 is a wasteful number, since it uses less digits than its factorization.

21363264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354 (or 335 counting only the distinct ones).

The product of its digits is 5184, while the sum is 27.

The square root of 21363264 is about 4622.0411075628. The cubic root of 21363264 is about 277.4741539113.

Adding to 21363264 its reverse (46236312), we get a palindrome (67599576).

The spelling of 21363264 in words is "twenty-one million, three hundred sixty-three thousand, two hundred sixty-four".