13131440 has 80 divisors (see below), whose sum is σ = 35354880. Its totient is φ = 4442880.

The previous prime is 13131421. The next prime is 13131449. The reversal of 13131440 is 4413131.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (13131449) 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 15 ways as a sum of consecutive naturals, for example, 73271 + ... + 73449.

It is an arithmetic number, because the mean of its divisors is an integer number (441936).

Almost surely, 2^13131440 is an apocalyptic number.

13131440 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 13131440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17677440).

13131440 is an abundant number, since it is smaller than the sum of its proper divisors (22223440).

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

13131440 is a wasteful number, since it uses less digits than its factorization.

13131440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330 (or 324 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 13131440 is about 3623.7328819879. The cubic root of 13131440 is about 235.9232729605.

Adding to 13131440 its reverse (4413131), we get a palindrome (17544571).

The spelling of 13131440 in words is "thirteen million, one hundred thirty-one thousand, four hundred forty".