13664 has 24 divisors (see below), whose sum is σ = 31248. Its totient is φ = 5760.

The previous prime is 13649. The next prime is 13669. The reversal of 13664 is 46631.

13664 = T₃₇ + T₃₈ + ... + T₅₀.

13664 is nontrivially palindromic in base 3.

13664 is an undulating number in base 11.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 13664.

It is not an unprimeable number, because it can be changed into a prime (13669) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194 + ... + 254.

It is an arithmetic number, because the mean of its divisors is an integer number (1302).

2¹³⁶⁶⁴ is an apocalyptic number.

13664 is a gapful number since it is divisible by the number (14) 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 13664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15624).

13664 is an abundant number, since it is smaller than the sum of its proper divisors (17584).

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

13664 is an equidigital number, since it uses as much as digits as its factorization.

13664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78 (or 70 counting only the distinct ones).

The product of its digits is 432, while the sum is 20.

The square root of 13664 is about 116.8931135696. The cubic root of 13664 is about 23.9070478681.

The spelling of 13664 in words is "thirteen thousand, six hundred sixty-four".