13581144 has 48 divisors (see below), whose sum is σ = 37486800. Its totient is φ = 4440384.

The previous prime is 13581137. The next prime is 13581149. The reversal of 13581144 is 44118531.

It is a happy number.

It is a zygodrome in base 3.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13581149) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2037 + ... + 5595.

It is an arithmetic number, because the mean of its divisors is an integer number (780975).

Almost surely, 2^13581144 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 13581144, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18743400).

13581144 is an abundant number, since it is smaller than the sum of its proper divisors (23905656).

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

13581144 is a wasteful number, since it uses less digits than its factorization.

13581144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3624 (or 3617 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 13581144 is about 3685.2603707201. The cubic root of 13581144 is about 238.5862720736.

Adding to 13581144 its reverse (44118531), we get a palindrome (57699675).

The spelling of 13581144 in words is "thirteen million, five hundred eighty-one thousand, one hundred forty-four".