21223360 has 56 divisors (see below), whose sum is σ = 52303680. Its totient is φ = 8193024.

The previous prime is 21223357. The next prime is 21223369. The reversal of 21223360 is 6332212.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223369) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8137 + ... + 10423.

Almost surely, 2^21223360 is an apocalyptic number.

21223360 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 21223360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26151840).

21223360 is an abundant number, since it is smaller than the sum of its proper divisors (31080320).

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

21223360 is a wasteful number, since it uses less digits than its factorization.

21223360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2333 (or 2323 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 19.

The square root of 21223360 is about 4606.8818087726. The cubic root of 21223360 is about 276.8671181643.

Adding to 21223360 its reverse (6332212), we get a palindrome (27555572).

The spelling of 21223360 in words is "twenty-one million, two hundred twenty-three thousand, three hundred sixty".