13443640 has 96 divisors (see below), whose sum is σ = 37141200. Its totient is φ = 4366656.

The previous prime is 13443631. The next prime is 13443643. The reversal of 13443640 is 4634431.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13443643) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 707551 + ... + 707569.

Almost surely, 2^13443640 is an apocalyptic number.

13443640 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 13443640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18570600).

13443640 is an abundant number, since it is smaller than the sum of its proper divisors (23697560).

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

13443640 is an equidigital number, since it uses as much as digits as its factorization.

13443640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82 (or 33 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 13443640 is about 3666.5569680560. The cubic root of 13443640 is about 237.7783403357.

The spelling of 13443640 in words is "thirteen million, four hundred forty-three thousand, six hundred forty".