12221418 has 64 divisors (see below), whose sum is σ = 28449792. Its totient is φ = 3463680.

The previous prime is 12221413. The next prime is 12221431. The reversal of 12221418 is 81412221.

It is a junction number, because it is equal to n+sod(n) for n = 12221394 and 12221403.

It is not an unprimeable number, because it can be changed into a prime (12221413) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 125946 + ... + 126042.

It is an arithmetic number, because the mean of its divisors is an integer number (444528).

Almost surely, 2^12221418 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12221418, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14224896).

12221418 is an abundant number, since it is smaller than the sum of its proper divisors (16228374).

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

12221418 is a wasteful number, since it uses less digits than its factorization.

12221418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 219.

The product of its digits is 256, while the sum is 21.

The square root of 12221418 is about 3495.9144726380. The cubic root of 12221418 is about 230.3423886023.

Adding to 12221418 its reverse (81412221), we get a palindrome (93633639).

The spelling of 12221418 in words is "twelve million, two hundred twenty-one thousand, four hundred eighteen".