12321216 has 42 divisors (see below), whose sum is σ = 35318192. Its totient is φ = 4106880.

The previous prime is 12321193. The next prime is 12321223. The reversal of 12321216 is 61212321.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 10120 + ... + 11271.

Almost surely, 2^12321216 is an apocalyptic number.

12321216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

12321216 is an abundant number, since it is smaller than the sum of its proper divisors (22996976).

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

12321216 is a wasteful number, since it uses less digits than its factorization.

12321216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21409 (or 21396 counting only the distinct ones).

The product of its digits is 144, while the sum is 18.

The square root of 12321216 is about 3510.1589707590. The cubic root of 12321216 is about 230.9676684946.

Adding to 12321216 its reverse (61212321), we get a palindrome (73533537).

The spelling of 12321216 in words is "twelve million, three hundred twenty-one thousand, two hundred sixteen".