12218520 has 128 divisors (see below), whose sum is σ = 40435200. Its totient is φ = 2939904.

The previous prime is 12218509. The next prime is 12218527. The reversal of 12218520 is 2581221.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12218527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 52324 + ... + 52556.

It is an arithmetic number, because the mean of its divisors is an integer number (315900).

Almost surely, 2^12218520 is an apocalyptic number.

12218520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a pronic number, being equal to 3495×3496.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12218520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20217600).

12218520 is an abundant number, since it is smaller than the sum of its proper divisors (28216680).

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

12218520 is a wasteful number, since it uses less digits than its factorization.

12218520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 289 (or 285 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 21.

The square root of 12218520 is about 3495.4999642397. The cubic root of 12218520 is about 230.3241805403.

Adding to 12218520 its reverse (2581221), we get a palindrome (14799741).

The spelling of 12218520 in words is "twelve million, two hundred eighteen thousand, five hundred twenty".