21353360 has 80 divisors (see below), whose sum is σ = 60103296. Its totient is φ = 6887424.

The previous prime is 21353357. The next prime is 21353383. The reversal of 21353360 is 6335312.

It is a tau number, because it is divible by the number of its divisors (80).

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 15 ways as a sum of consecutive naturals, for example, 8399 + ... + 10641.

Almost surely, 2^21353360 is an apocalyptic number.

21353360 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 21353360, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30051648).

21353360 is an abundant number, since it is smaller than the sum of its proper divisors (38749936).

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

21353360 is a wasteful number, since it uses less digits than its factorization.

21353360 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2280 (or 2274 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 23.

The square root of 21353360 is about 4620.9695952257. The cubic root of 21353360 is about 277.4312683172.

Adding to 21353360 its reverse (6335312), we get a palindrome (27688672).

The spelling of 21353360 in words is "twenty-one million, three hundred fifty-three thousand, three hundred sixty".