13221144 has 56 divisors (see below), whose sum is σ = 37183860. Its totient is φ = 4405104.

The previous prime is 13221139. The next prime is 13221149. The reversal of 13221144 is 44112231.

13221144 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (13221139) and next prime (13221149).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13221149) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 4699 + ... + 6965.

Almost surely, 2^13221144 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13221144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18591930).

13221144 is an abundant number, since it is smaller than the sum of its proper divisors (23962716).

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

13221144 is an equidigital number, since it uses as much as digits as its factorization.

13221144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2291 (or 2272 counting only the distinct ones).

The product of its digits is 192, while the sum is 18.

The square root of 13221144 is about 3636.0891078190. The cubic root of 13221144 is about 236.4592703558.

Adding to 13221144 its reverse (44112231), we get a palindrome (57333375).

The spelling of 13221144 in words is "thirteen million, two hundred twenty-one thousand, one hundred forty-four".