21324616 has 16 divisors (see below), whose sum is σ = 40129200. Its totient is φ = 10623504.

The previous prime is 21324571. The next prime is 21324619. The reversal of 21324616 is 61642312.

It is a zygodrome in base 9.

It is not an unprimeable number, because it can be changed into a prime (21324619) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2446 + ... + 6973.

It is an arithmetic number, because the mean of its divisors is an integer number (2508075).

Almost surely, 2^21324616 is an apocalyptic number.

It is an amenable number.

21324616 is a deficient number, since it is larger than the sum of its proper divisors (18804584).

21324616 is a wasteful number, since it uses less digits than its factorization.

21324616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9708 (or 9704 counting only the distinct ones).

The product of its digits is 1728, while the sum is 25.

The square root of 21324616 is about 4617.8583780796. The cubic root of 21324616 is about 277.3067279602.

Adding to 21324616 its reverse (61642312), we get a palindrome (82966928).

The spelling of 21324616 in words is "twenty-one million, three hundred twenty-four thousand, six hundred sixteen".