21384360 has 96 divisors (see below), whose sum is σ = 70087680. Its totient is φ = 5654400.

The previous prime is 21384359. The next prime is 21384361. The reversal of 21384360 is 6348312.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21384359) and next prime (21384361).

It is not an unprimeable number, because it can be changed into a prime (21384361) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 68605 + ... + 68915.

It is an arithmetic number, because the mean of its divisors is an integer number (730080).

Almost surely, 2^21384360 is an apocalyptic number.

21384360 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 21384360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35043840).

21384360 is an abundant number, since it is smaller than the sum of its proper divisors (48703320).

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

21384360 is a wasteful number, since it uses less digits than its factorization.

21384360 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 519 (or 512 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 21384360 is about 4624.3226531028. The cubic root of 21384360 is about 277.5654581399.

The spelling of 21384360 in words is "twenty-one million, three hundred eighty-four thousand, three hundred sixty".