21318244 has 12 divisors (see below), whose sum is σ = 37348864. Its totient is φ = 10647144.

The previous prime is 21318223. The next prime is 21318257. The reversal of 21318244 is 44281312.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1897 + ... + 6799.

Almost surely, 2^21318244 is an apocalyptic number.

It is an amenable number.

21318244 is a deficient number, since it is larger than the sum of its proper divisors (16030620).

21318244 is a wasteful number, since it uses less digits than its factorization.

21318244 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5994 (or 5992 counting only the distinct ones).

The product of its digits is 1536, while the sum is 25.

The square root of 21318244 is about 4617.1683963226. The cubic root of 21318244 is about 277.2791045710.

Adding to 21318244 its reverse (44281312), we get a palindrome (65599556).

The spelling of 21318244 in words is "twenty-one million, three hundred eighteen thousand, two hundred forty-four".