13440640 has 32 divisors (see below), whose sum is σ = 32133060. Its totient is φ = 5376000.

The previous prime is 13440617. The next prime is 13440653. The reversal of 13440640 is 4604431.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 12787776 + 652864 = 3576^2 + 808^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9861 + ... + 11140.

Almost surely, 2^13440640 is an apocalyptic number.

13440640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13440640 is an abundant number, since it is smaller than the sum of its proper divisors (18692420).

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

13440640 is an equidigital number, since it uses as much as digits as its factorization.

13440640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21020 (or 21008 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 22.

The square root of 13440640 is about 3666.1478420817. The cubic root of 13440640 is about 237.7606519693.

The spelling of 13440640 in words is "thirteen million, four hundred forty thousand, six hundred forty".