13243440 has 80 divisors (see below), whose sum is σ = 46925568. Its totient is φ = 3026688.

The previous prime is 13243429. The next prime is 13243453. The reversal of 13243440 is 4434231.

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

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2262 + ... + 5621.

Almost surely, 2^13243440 is an apocalyptic number.

13243440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13243440 is an abundant number, since it is smaller than the sum of its proper divisors (33682128).

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

13243440 is a wasteful number, since it uses less digits than its factorization.

13243440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7906 (or 7900 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 21.

The square root of 13243440 is about 3639.1537477826. The cubic root of 13243440 is about 236.5921165266.

Adding to 13243440 its reverse (4434231), we get a palindrome (17677671).

The spelling of 13243440 in words is "thirteen million, two hundred forty-three thousand, four hundred forty".