12216438 has 96 divisors (see below), whose sum is σ = 31370976. Its totient is φ = 3400704.

The previous prime is 12216437. The next prime is 12216439. The reversal of 12216438 is 83461221.

12216438 is a `hidden beast` number, since 1 + 221 + 6 + 438 = 666.

It is an interprime number because it is at equal distance from previous prime (12216437) and next prime (12216439).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12216431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 147145 + ... + 147227.

It is an arithmetic number, because the mean of its divisors is an integer number (326781).

Almost surely, 2^12216438 is an apocalyptic number.

12216438 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 12216438, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15685488).

12216438 is an abundant number, since it is smaller than the sum of its proper divisors (19154538).

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

12216438 is a wasteful number, since it uses less digits than its factorization.

12216438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 158 (or 155 counting only the distinct ones).

The product of its digits is 2304, while the sum is 27.

The square root of 12216438 is about 3495.2021400772. The cubic root of 12216438 is about 230.3110976087.

Adding to 12216438 its reverse (83461221), we get a palindrome (95677659).

The spelling of 12216438 in words is "twelve million, two hundred sixteen thousand, four hundred thirty-eight".