13887640 has 64 divisors (see below), whose sum is σ = 35652960. Its totient is φ = 4823040.

The previous prime is 13887611. The next prime is 13887641. The reversal of 13887640 is 4678831.

It is a happy number.

13887640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 13887640.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13887641) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8055 + ... + 9625.

Almost surely, 2^13887640 is an apocalyptic number.

13887640 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 13887640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17826480).

13887640 is an abundant number, since it is smaller than the sum of its proper divisors (21765320).

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

13887640 is a wasteful number, since it uses less digits than its factorization.

13887640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1612 (or 1608 counting only the distinct ones).

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 13887640 is about 3726.6124027057. The cubic root of 13887640 is about 240.3677233308.

It can be divided in two parts, 138 and 87640, that added together give a palindrome (87778).

The spelling of 13887640 in words is "thirteen million, eight hundred eighty-seven thousand, six hundred forty".