13640 has 32 divisors (see below), whose sum is σ = 34560. Its totient is φ = 4800.

The previous prime is 13633. The next prime is 13649. The reversal of 13640 is 4631.

13640 = T₂₁ + T₂₂ + ... + T₄₄.

13640 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

13640 is strictly pandigital in base 6.

It is not an unprimeable number, because it can be changed into a prime (13649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 425 + ... + 455.

It is an arithmetic number, because the mean of its divisors is an integer number (1080).

2¹³⁶⁴⁰ is an apocalyptic number.

13640 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 13640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17280).

13640 is an abundant number, since it is smaller than the sum of its proper divisors (20920).

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

13640 is a wasteful number, since it uses less digits than its factorization.

13640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53 (or 49 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 13640 is about 116.7904105653. The cubic root of 13640 is about 23.8930425644.

Subtracting from 13640 its reverse (4631), we obtain a palindrome (9009).

The spelling of 13640 in words is "thirteen thousand, six hundred forty".