13438640 has 40 divisors (see below), whose sum is σ = 31457808. Its totient is φ = 5338880.

The previous prime is 13438639. The next prime is 13438673. The reversal of 13438640 is 4683431.

It is a tau number, because it is divible by the number of its divisors (40).

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 13355 + ... + 14325.

Almost surely, 2^13438640 is an apocalyptic number.

13438640 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 13438640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15728904).

13438640 is an abundant number, since it is smaller than the sum of its proper divisors (18019168).

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

13438640 is a wasteful number, since it uses less digits than its factorization.

13438640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1157 (or 1151 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 29.

The square root of 13438640 is about 3665.8750660654. The cubic root of 13438640 is about 237.7488582628.

The spelling of 13438640 in words is "thirteen million, four hundred thirty-eight thousand, six hundred forty".