12213728 has 24 divisors (see below), whose sum is σ = 24290280. Its totient is φ = 6044800.

The previous prime is 12213689. The next prime is 12213731. The reversal of 12213728 is 82731221.

It is a junction number, because it is equal to n+sod(n) for n = 12213697 and 12213706.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 1343 + ... + 5121.

It is an arithmetic number, because the mean of its divisors is an integer number (1012095).

Almost surely, 2^12213728 is an apocalyptic number.

It is an amenable number.

12213728 is a deficient number, since it is larger than the sum of its proper divisors (12076552).

12213728 is a wasteful number, since it uses less digits than its factorization.

12213728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3890 (or 3882 counting only the distinct ones).

The product of its digits is 1344, while the sum is 26.

The square root of 12213728 is about 3494.8144442874. The cubic root of 12213728 is about 230.2940662058.

Adding to 12213728 its reverse (82731221), we get a palindrome (94944949).

The spelling of 12213728 in words is "twelve million, two hundred thirteen thousand, seven hundred twenty-eight".