18688 has 18 divisors (see below), whose sum is σ = 37814. Its totient is φ = 9216.

The previous prime is 18679. The next prime is 18691. The reversal of 18688 is 88681.

It can be written as a sum of positive squares in only one way, i.e., 16384 + 2304 = 128^2 + 48^2 .

It is a nialpdrome in base 8 and base 12.

It is a zygodrome in base 8.

It is an unprimeable number.

18688 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a pernicious number, because its binary representation contains a prime number (3) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 220 + ... + 292.

2¹⁸⁶⁸⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18907).

18688 is an abundant number, since it is smaller than the sum of its proper divisors (19126).

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

18688 is an frugal number, since it uses more digits than its factorization.

18688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89 (or 75 counting only the distinct ones).

The product of its digits is 3072, while the sum is 31.

The square root of 18688 is about 136.7040599251. The cubic root of 18688 is about 26.5371497475.

The spelling of 18688 in words is "eighteen thousand, six hundred eighty-eight".