12013220 has 48 divisors (see below), whose sum is σ = 27079920. Its totient is φ = 4460544.

The previous prime is 12013219. The next prime is 12013223. The reversal of 12013220 is 2231021.

12013220 = 255² + 256² + ... + 374².

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 64 + 12013156 = 8^2 + 3466^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12013223) 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 15 ways as a sum of consecutive naturals, for example, 30062 + ... + 30458.

It is an arithmetic number, because the mean of its divisors is an integer number (564165).

Almost surely, 2^12013220 is an apocalyptic number.

12013220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12013220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13539960).

12013220 is an abundant number, since it is smaller than the sum of its proper divisors (15066700).

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

12013220 is a wasteful number, since it uses less digits than its factorization.

12013220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 512 (or 510 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 12013220 is about 3466.0092325324. The cubic root of 12013220 is about 229.0268905577.

Adding to 12013220 its reverse (2231021), we get a palindrome (14244241).

The spelling of 12013220 in words is "twelve million, thirteen thousand, two hundred twenty".