13665438 has 48 divisors (see below), whose sum is σ = 31337280. Its totient is φ = 4296768.

The previous prime is 13665413. The next prime is 13665481. The reversal of 13665438 is 83456631.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24256 + ... + 24812.

It is an arithmetic number, because the mean of its divisors is an integer number (652860).

Almost surely, 2^13665438 is an apocalyptic number.

13665438 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 13665438, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15668640).

13665438 is an abundant number, since it is smaller than the sum of its proper divisors (17671842).

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

13665438 is a wasteful number, since it uses less digits than its factorization.

13665438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641 (or 638 counting only the distinct ones).

The product of its digits is 51840, while the sum is 36.

The square root of 13665438 is about 3696.6793206877. The cubic root of 13665438 is about 239.0788649825.

The spelling of 13665438 in words is "thirteen million, six hundred sixty-five thousand, four hundred thirty-eight".