21330344 has 32 divisors (see below), whose sum is σ = 45878400. Its totient is φ = 9107520.

The previous prime is 21330313. The next prime is 21330347. The reversal of 21330344 is 44303312.

It is not an unprimeable number, because it can be changed into a prime (21330347) 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, 19574 + ... + 20634.

It is an arithmetic number, because the mean of its divisors is an integer number (1433700).

Almost surely, 2^21330344 is an apocalyptic number.

It is an amenable number.

21330344 is an abundant number, since it is smaller than the sum of its proper divisors (24548056).

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

21330344 is a wasteful number, since it uses less digits than its factorization.

21330344 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1433 (or 1429 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 20.

The square root of 21330344 is about 4618.4785373540. The cubic root of 21330344 is about 277.3315548353.

Adding to 21330344 its reverse (44303312), we get a palindrome (65633656).

The spelling of 21330344 in words is "twenty-one million, three hundred thirty thousand, three hundred forty-four".